Neurokinin receptor mRNA localization in human midbrain dopamine neurons

The results of revision elbow arthroplasty with use of the semiconstrained Mayo-modified Coonrad implant in forty-one patients were reviewed retrospectively. The average duration of follow-up was six years (range, two to thirteen years). At the time of the latest follow-up evaluation, thirty-eight patients were able to perform activities of daily living, one had a stiff elbow because of heterotopic ossification, one had weakness secondary to an injury of the radial nerve, and one had an unstable elbow after removal of the prosthesis because of recurrent aseptic loosening. Fourteen patients sustained either a fracture or a perforation of the cortex at the time of removal of the primary implant. Three of these patients had an injury of the radial nerve; the injury was due to extravasation of the cement from a cortical defect in two of them and was sustained during removal of the cement in one. Eight patients had an intraoperative or postoperative complication that necessitated additional operative intervention. Postoperatively, twenty-two patients had complete relief of pain and sixteen had mild discomfort. Three patients remained disabled: one, because of pain secondary to loosening of the component; one, because of a pre-existing nerve injury; and one, because of the residual effects of an intraoperative injury of the radial nerve. The average Mayo elbow performance score was 87 +/- 16 points at the latest follow-up evaluation, compared with 44 +/- 17 points preoperatively (p < 0.0001). Revision elbow arthroplasty restored function to the patients who had had a failed prosthesis without infection.     

Sacrospinalis muscle-pedicle bone graft in posterolateral fusion for spondylolisthesis

From 1984 to 1995, 68 ankylosed elbows and 11 which were unstable after trauma were replaced in India by Baksi sloppy hinge prostheses. The mean age of the patients was 28.6 years (17 to 70) and the mean follow-up 9.6 years (2 to 13.5). Of the 68 ankylosed elbows, 59 (87%) regained a mean arc of painless movement of 88.5 degrees (27 to 115). The mean improvement of supination was 24 degrees and of pronation 16.5 degrees . There were 54 good results (80%), eight fair and three poor. There were two complete failures due to infection, and one due to a broken humeral stem. Of the 11 unstable elbows, the nine with good results had a mean arc of 125 degrees (15 to 140) of painless stable movement, with a mean improvement in supination of 26 degrees and of pronation of 19.5 degrees . There was one fair result and one failure due to loosening with subsequent late infection. There were significant complications in 14 cases with infection in seven and aseptic loosening in four. Patients with loosening or late removal of the prosthesis often retained reasonably stable elbow movement because periprosthetic fibrosis had connected the approximated bone ends, and muscle balance had been restored.     

Total replacement of the elbow joint

Total replacement of the elbow joint has been performed on 86 elbows at the Mayo Clinic, all but 15 in patients with rheumatoid arthritis. The Mayo design, which replaces both radiohumeral and humeroulnar joints, was used in 41 elbows, almost all in rheumatoid patients, with 71% good results. The Coonrad hinge with polyethylene bushings was used in 34 elbows; it was successful in 64% of rheumatoid patients, but failed in 46% of posttraumatic patients with bone loss. Previous designs have failed because of humeral loosening. Total elbow replacement is a technique still to be perfected in medical centers before general release.     

Analysis and Transition Probabilities for the Na2 B1Piu --> X1Sigma+g System Using as Excitation the 4727-? Ar+ Laser Line

The results of operative resection of a post-traumatic proximal radioulnar synostosis performed by one surgeon in eighteen limbs of seventeen consecutive patients during an eight-year period were reviewed retrospectively. The resection was performed an average of nineteen months after the injury; eight limbs had the resection less than twelve months after the injury. A free fat graft was used in the first eight patients. No adjuvant non-steroidal anti-inflammatory medication or low-dose radiation was used postoperatively as prophylaxis against heterotopic ossification. We classified the proximal radioulnar synostoses into three subgroups: A indicated a synostosis at or distal to the bicipital tuberosity (four limbs), B indicated a synostosis involving the radial head and the proximal radioulnar joint (seven limbs), and C indicated a synostosis that was contiguous with bone extending across the elbow to the distal aspect of the humerus (seven limbs). The patients were followed for an average of thirty-four months (range, twenty-four to sixty months). The synostosis recurred in one patient, the only patient in the series who had sustained a closed head injury at the time of the initial injury. Additional complications included a fracture of the ulna, a broken pin on a hinged elbow distractor, and dislodgment of a free nonvascularized fat graft in one patient each. The seventeen limbs that did not have a recurrence regained an average of 139 degrees of rotation of the forearm. With the number of patients available, we could not detect a significant relationship between subsequent rotation of the forearm and the size of the synostosis, the use of interpositional fat, or the concomitant use of a hinged elbow distractor. The eight limbs that had resection of the synostosis less than twelve months after the injury regained an average of 144 degrees of rotation compared with 134 degrees in the nine limbs that had resection at least twelve months after the injury. This difference could not be shown to be significant. In this series, operative resection of a post-traumatic proximal radioulnar synostosis led to good results despite the lack of adjuvant radiation therapy or anti-inflammatory medication.     

Total elbow arthroplasty as primary treatment for distal humeral fractures in elderly patients

We retrospectively reviewed the results of primary total elbow arthroplasty for the treatment of an acute fracture of the distal aspect of the humerus in twenty consecutive patients (twenty-one elbows) who had a mean age of seventy-two years (range, forty-eight to ninety-two years) at the time of the injury. The patients were managed between November 1982 and October 1992. The presence of rheumatoid arthritis in nine patients (ten elbows) influenced the choice of treatment. The mean interval between the injury and the total elbow arthroplasty was seven days (range, one to twenty-five days). The mean duration of postoperative hospitalization was seven days (range, four to thirteen days). The mean duration of follow-up was 3.3 years (range, three months to 10.5 years). All patients were followed for a minimum of two years or until the time of death; the duration of follow-up was less than two years for three patients who died. None of the patients were lost to follow-up. Twenty implants were intact at the latest follow-up examination. One patient had a revision total elbow arthroplasty twenty months after the index procedure because of a fracture of the ulnar component sustained in a fall on the outstretched arm. On the basis of the Mayo elbow performance score, fifteen elbows had an excellent result and five had a good result; there were inadequate data for one elbow. There were no fair or poor results. The mean arc of flexion was 25 to 130 degrees. There was no evidence of loosening on the radiographs. Postoperative complications included fracture of the ulnar component in one patient, ulnar neurapraxia in three, and reflex sympathetic dystrophy in one. The results suggest that total elbow arthroplasty can be an alternative form of treatment of a severely comminuted fracture of the distal aspect of the humerus in older patients even in the presence of rheumatoid arthritis. This procedure is not an alternative to osteosynthesis in younger patients.     

Range of motion and complications after postburn heterotopic bone excision about the elbow

OBJECTIVE: To review the results of surgical management of heterotopic ossification about the elbow in burned patients. DESIGN: Retrospective analysis with long-term patient follow-up. MATERIALS AND METHODS: Eleven patients with 16 elbows requiring surgery were admitted between January 1, 1982 and December 31, 1993. A posterior approach to the elbow with release of the encased ulnar nerve +/- anterior transposition and transolecranon osteotomy to access extensive bone formation in the olecranon fossa was employed. Eight patients (11 elbows) were available for long-term follow-up conducted at mean 50 +/- 13 months after surgery. Long-term follow-up consisted of measurement of range of elbow motion, as well as clinical assessment of ulnar nerve function. MAIN RESULTS: For the 11 elbows examined postoperatively, the mean range of motion preoperatively in flexion-extension was 11 degrees +/- 5 degrees compared to 89 degrees +/- 12 degrees postoperatively (p < 0.001). Three patients with poor long-term results had ankylosis of the joint preoperatively. Of four patients with ulnar nerve paresis preoperatively, none had ulnar nerve dysfunction at follow-up. Of 16 elbows operated on, four (25%) had postoperative complications. Two suffered soft-tissue breakdown with hardware exposure requiring abdominal flap closure, one early failure of olecranon fixation, and one late infected hardware. CONCLUSIONS: Surgery for both limited range of motion as well as ulnar nerve compression is effective in cases of heterotopic ossification about the elbows of burned patients. Early operative intervention is indicated in progressive disease, particularly ulnar nerve palsy, if soft-tissue quality is adequate. Complications with 25% of elbows suggest that use of olecranon osteotomy for joint access may warrant review.     

The column procedure: a limited lateral approach for extrinsic contracture of the elbow

Thirty-eight elbows (thirty-seven patients) with an extrinsic contracture were treated operatively with a limited lateral approach to the anterior and posterior aspects of the capsule. Because the procedure elevates muscles from the anterior and posterior aspects of the lateral supracondylar osseous ridge, we called it the column procedure. The mean preoperative arc of flexion was 49 degrees (from 52 to 101 degrees). At a mean of forty-three months (range, twenty-four to seventy-four months) postoperatively, the mean arc of flexion was 94 degrees (from 27 to 121 degrees). The mean total gain in the arc of flexion-extension was 45 degrees; thirty-four elbows (89 percent) had an improved range of motion at the latest follow-up examination. Overall, thirty-one elbows (82 percent) had a satisfactory result. Greater improvement was obtained in elbows that had had severe stiffness (a total arc of 31 to 60 degrees) or very severe stiffness (a total arc of 30 degrees or less) or that had had a combined flexion and extension contracture. A complication occurred in four elbows (11 percent). A hematoma developed in two elbows and impaired the final outcome in one of them. Two elbows had transient ulnar paresthesia, which resolved spontaneously. The arc of flexion obtained at the time of the operation was lost in ten elbows (26 percent) after an initial period of improvement; at the latest follow-up evaluation, four of these elbows had a mean decrease in the arc of flexion of 24 degrees compared with preoperatively. The column procedure is associated with a low rate of complications and is safe and effective for the treatment of a limitation in flexion or extension resulting from an extrinsic contracture of the elbow.     

Semiconstrained total elbow arthroplasty

Diminution of elbow function may be both embarrassing and severely disabling, especially in patients with multiple arthritic joints. Over the past century, multiple techniques of soft tissue reconstruction of the elbow have been advocated. In general, they do not compare well with total elbow arthroplasty. Arthrolysis has often resulted in little improvement of elbow motion and interposition arthroplasty to instability. Synovectomy may however offer satisfactory relief of disability for the rheumatoid elbow provided that initially there is little evidence of joint destruction. The major problem with rigidly linked total elbow arthroplasty has been a high incidence of prosthetic loosening. Biomechanical analysis has shown that high moments tend to disrupt the osseousmethacrylate junction in the humoral medulary canal. Development of a semi-constrained total elbow prosthesis transfers the developed stress to the collateral soft tissues and reduces prosthetic loosening to approximately 3 per cent. This is about one-tenth of the incidence of loosening of the hinge type arthroplasty. This reduction in prosthetic loosening has been coupled with excellent gains in flexion and estension. However, improvement in forearm rotation has not been predictable, especially in elbows exhibiting preoperative fusion or fibrous ankylosis. Though the semi-counstrained total elbow has only been generally available for 3 years, a review of these results justifies its continued use for elbow reconstruction.     

Musculocutaneous neurectomy for spastic elbow flexion in non-functional upper extremities in adults

The charts of twenty-nine patients who had undergone thirty musculocutaneous neurectomies for acquired spasticity of the elbow in a non-functional upper extremity were reviewed. The most common causes of the spasticity were cerebrovascular accident (59 per cent) and head injury (24 per cent). The aims of the operation were to increase the patient's capacity for self-care and to improve ambulation, personal hygiene, and appearance. Patients who had 30-degree flexion contractures preoperatively did not require a cast postoperatively; those who had 30 to 75-degree flexion contractures preoperatively required a cast postoperatively; and patients who had flexion contractures of more than 75 degrees preoperatively required a concomitant release of soft tissue in the elbow and application of a cast postoperatively. One patient who was operated on to improve appearance had no active elbow flexion postoperatively and was regarded as having a poor result. Musculocutaneous neurectomy is a safe, reliable procedure for treating the spastic elbow in the non-functional upper extremity.     

Angiotensin II inhibits long-term potentiation within the lateral nucleus of the amygdala through AT1 receptors

We have treated 16 patients with recurrent complex elbow instability using a hinged external fixator. All patients had instability, dislocation or subluxation of the ulnohumeral joint. The injuries were open in eight patients and were associated with 20 other fractures and five peripheral nerve injuries. Two patients had received initial treatment from us; 14 had previously had a mean of 2.1 unsuccessful surgical procedures (1 to 6). The fixator was applied at a mean of 4.8 weeks (0 to 9) after the injury and remained on the elbow for a mean of 8.5 weeks (6 to 11). After treatment we found the mean range of flexion-extension to be 105 degrees (65 to 140). At a final follow-up of 23 months (14 to 40), the mean Morrey score was 84 (49 to 96): this translated into one poor, three fair, ten good and two excellent results. Complications included one fractured humeral pin, one temporary palsy of the radial nerve, one recurrent instability, one wound infection, one severe pin-track infection and one patient with reflex sympathetic dystrophy. Although technically demanding, the use of the fixator is an important advance in the management of recurrent complex elbow instability after failure of conventional treatment.     

Scapholunate ligament repair and capsulodesis for the treatment of static scapholunate dissociation

Twenty-four patients were treated with scapholunate ligament repair and dorsal capsulodesis for scapholunate dissociation. Seventeen patients were available for follow-up at an average of 30 months. The average interval between injury and surgery was 3 months. At final follow-up, no patients were pain-free. Average total wrist motion was 60% and grip strength 70% of the opposite normal side. The average preoperative scapholunate angle was 78 degrees and was corrected to a normal 47 degrees at surgery. The average final scapholunate angle was 72 degrees, which was not significantly different from the preoperative value. The scapholunate gap likewise was not significantly changed postoperatively. Only two patients had an excellent or good outcome using a clinical grading system, and six out of 17 scored good or excellent using a radiographic grading system. In conclusion, repair of the scapholunate ligament with dorsal capsulodesis failed to provide consistent pain relief and maintain carpal alignment in patients with static scapholunate instability.     

Salvage surgery for lateral tennis elbow

We undertook a retrospective analysis of 34 patients (35 elbows) who had prior failed surgical intervention for lateral tennis elbow. Revision surgeries were performed between 1979 and 1994. Each patient's non-operative and operative history was recorded before our salvage revision surgery. At revision surgery, findings included residual tendinosis of the extensor carpi radialis brevis tendon in 34 of 35 elbows. In 27 elbows, the pathologic changes in the extensor carpi radialis brevis tendon had not been previously addressed at all, and in 7 elbows the damaged tissue had not been completely excised. Salvage surgery included excision of pathologic tissue in the extensor carpi radialis brevis tendon origin combined with excision of excessive scar tissue and repair of the extensor aponeurosis when necessary. Based on a 40-point functional rating scale proposed here, 83% of the elbows (29 of 35) had good or excellent results at an average followup of 64 months (range, 17 months to 17 years). To prevent failure of surgical treatment for tennis elbow, the pathologic tissue usually present in the extensor carpi radialis brevis tendon should be resected. Release operations, which weaken the extensor aponeurosis but fail to address the pathoanatomic changes, are not recommended.     

Synovectomy of the elbow and radial head excision in rheumatoid arthritis. Predictive factors and long-term outcome

We carried out a survival analysis of elbow synovectomy (ES) and excision of the radial head (RHE) performed on 171 rheumatoid elbows. The failure criteria were revision surgery (performed or desired) and/or the presence of significant or severe pain. The cumulative survival was 81% at one year which thereafter decreased by an average of 2.6% per year. The strongest predictor for success was a low preoperative range of supination-pronation when corresponding survival curves were compared. A low range of flexion-extension also predicted failure. Combining both factors gave better prediction (failure: 6.3% v 67%), but a long duration of elbow symptoms before surgery predicted failure (72%, p = 0.04). At review, there was a mean gain of 50 degrees in supination-pronation and 11 degrees in flexion-extension; both correlated with success. Failure correlated with recurrence of synovitis, elbow instability, ulnar neuropathy, poor general mobility and poor upper-limb function. The last was independently affected by the severity of RA in the ipsilateral shoulder. Our findings show that although the short-term result of ES and RHE in rheumatoid arthritis is good, the long-term outcome is poor except in a subgroup with more than 50% limitation of forearm rotation.     

Patellar tracking after total knee arthroplasty. The effect of tibial tray malrotation and articular surface configuration

The effect of total knee arthroplasty (TKA) with neutrally aligned and malrotated tibial trays was studied in five fresh anatomic specimen knees. Patellar shift, tilt, and rotation, and the rotational position of the tibia were measured in normal knees and after TKA with the Ortholoc Modular knee system. Both semiconstrained and unconstrained articular surfaces were assessed in the neutral position and at anatomic, 15 degrees internal, and 15 degrees external rotation of the tibial tray. After TKA, the patellae shifted slightly medially in the early phase of knee flexion because the anterior lateral flange of the femoral component was longer than the lateral trochlea of the femur and because the tibia rotated internally. The raised lateral flange on the femoral component tilted the patella medially at full extension after TKA. The semiconstrained tray allowed minimal tibial rotation because of its articular configuration. As much as 15 degrees malrotation of the unconstrained tibial tray did not affect patellar tracking. The semiconstrained tibial tray in the neutral position had almost the same patellar tracking as the unconstrained tray, but at 15 degrees external rotation, the semiconstrained tray internally rotated the tibia, leading to medial shift of the patella. Although 15 degrees internal rotation caused external rotation of the tibia, the patella did not shift as much laterally, despite the increase in the Q angle.     

Total hip arthroplasty with use of second-generation cementing techniques. An eighteen-year-average follow-up study

In this report, we present the results of a further follow-up of a series of 140 consecutive patients (161 hips) who had had a primary total hip arthroplasty with insertion of a bead-blasted monoblock femoral component with use of so-called second-generation cementing techniques. The average age of the patients at the time of the arthroplasty was sixty-one years (range, twenty-one to eighty-five years). Sixty-seven patients (seventy-seven hips) died less than seventeen years after the index operation. The remaining seventy-three patients (eighty-four hips) were followed for an average of eighteen years (range, seventeen to twenty years). No patient was lost to follow-up. In the entire group of 161 hips, over the twenty-year span of the study, eight femoral components (5 percent) and twenty-eight acetabular components (17 percent) had been revised because of aseptic loosening. Of the seventy-seven hips in the sixty-seven patients who died, four had been revised because of aseptic loosening of the acetabular component only; one, because of aseptic loosening of the femoral component only; and one, because of aseptic loosening of both components. Of the eighty-four hips in the seventy-three patients who were alive at least seventeen years after the index arthroplasty, twenty-four hips (29 percent) in twenty-one patients had had revision of one or both components for any reason. Twenty-three acetabular components (27 percent) and six femoral components (7 percent) had been revised because of aseptic loosening. An additional two hips (2 percent) in two patients were loose according to radiographic criteria but had not been revised. Of the sixty-five all-polyethylene acetabular components that had been inserted with cement and were in patients who were alive at least seventeen years postoperatively, fifteen (23 percent) had been revised because of aseptic loosening. An additional seventeen cups (26 percent) were loose according to radiographic criteria. Thus, a total of thirty-two cups (49 percent) had been revised because of loosening or were loose but had not been revised at the time of the latest follow-up. The femoral components that had been inserted with use of second-generation cementing techniques fared better than did the acetabular components that had been inserted with these techniques during the same time-period. We found that assessment of all postoperative radiographs rather than only those that had been made immediately postoperatively increased the accuracy of the grading of the cement around the femoral component. Subsequent radiographs frequently had been made at different projections, which revealed new findings, consisting primarily of previously undetected voids, areas of thin cement, and defects in the cement mantle. Thus, we now use all available radiographs to determine the grade of the cement.     

Automated seeded lesion segmentation on digital mammograms

The clinical results of eighty-four total hip arthroplasties performed through a transtrochanteric approach in sixty-seven patients who had a high dislocation of the hip (the femoral head completely out of the acetabulum), from 1976 to 1994, were reviewed. The acetabular component was placed in the true acetabulum and the femur was shortened at the level of the femoral neck, along with release of the psoas tendon and the small external rotators, in order to facilitate reduction of the components and to avoid neurovascular complications. Eleven hip prostheses (13 per cent) failed at a mean of 6.4 years (range, two months to sixteen years) postoperatively; the failure was due to aseptic loosening of both components in four hips, aseptic loosening of the stem only in three, late infection in three, and malpositioning of the acetabular component that caused recurrent dislocations in one. The other seventy-three hips were functioning well at the latest follow-up examination, two to twenty years (mean, 7.1 years) postoperatively. The overall cumulative rate of success was 92.4 per cent (95 per cent confidence interval, 89.5 to 95.3 per cent) at five years and 88.0 per cent (95 per cent confidence interval, 82.2 to 93.8 per cent) at ten years. We believe that this operative technique of total hip arthroplasty is effective for the treatment of the difficult condition of high dislocation of the hip.     

Increased erythrocyte deformability in fetal erythropoiesis and in erythrocytes deficient in glucose-6-phosphate dehydrogenase and other glycolytic enzymes

We evaluated the results of an excision of the radial head in 25 patients (27 operated-on elbows) younger than 18 years with stiff painful radiocapitellar joints. The mean age was 14.2 years (range, 4.6-17.8 years) with average follow-up of 7.8 years. Analysis of the results with a postoperative elbow score revealed excellent or good results in 19 of the 27 elbows of patients. Skeletal maturity of the patient did not alter the results based on the rating scale. Revision surgery to remove appositional bone growth was needed in six of the 12 posttraumatic cases and one of 15 developmental elbows. Cubitus valgus, wrist pain, and ulnar neuropathy were not clinical problems at follow-up examination. Excision of the radial head was beneficial for 70% of patients younger than 18 years with stiff, painful radiocapitellar joints. Results were not improved in patients who had reached skeletal maturity.     

Pregnancy after pancreas transplantation in the cyclosporine era: report from the International Pancreas Transplant Registry

In haemophilic arthropathy there is a progressive limitation of the range of motion (ROM) which may lead to disabilities in the activities of daily living (ADL). In the literature the pathology of haemophilic arthropathy is described extensively, but only one paper describing functional limitations caused by limited range of motion (LOM) in haemophilia was found. The aim of the pilot study was to estimate on theoretical grounds, how many patients with haemophilia might suffer from functional disabilities. MATERIAL: ROM of elbows, knees and ankles of 155 Haemophilia A and B patients. METHODS: Flexion and extension were measured with an ordinary goniometer. The ROM of joints of patients with haemophilia was compared with normal values. RESULTS: 39 of 155 patients had a normal ROM in both elbows; 22 in one elbow; 34 patients had disabilities in ADL with both arms; 14 with one arm; 18 were able to compensate; 89 had no problems; 79 of 155 patients had a near normal ROM of both knees; 38 patients could not ride an ordinary bicycle. CONCLUSION: Only limited data are available concerning the normal ROM needed for individual ADL. Until additional data are available, it is not possible to predict which patients will be disabled in their activities of daily living and individual counselling should be done during the yearly outpatient comprehensive care clinics. Conservative and surgical measures should be taken to ensure elbow flexion of at least 120 degrees and knee flexion of 100 degrees for Western societies. In Asian countries patients with haemophilia need maximum knee flexion and ankle dorsi flexion.     

Late treatment of brachial plexus palsy secondary to birth injuries: rotational osteotomy of the proximal part of the humerus

We retrospectively reviewed the results of rotational osteotomy that had been performed distal to the surgical neck of the humerus in twenty-two patients who had sustained an injury of the brachial plexus at birth. Eighteen patients had a lesion of the superior trunk of the brachial plexus (the fifth and sixth cervical nerve roots), and four had involvement of the entire brachial plexus. The patients ranged in age from four to seventeen years old (average age, ten years and three months old) at the time of the operation. The average duration of follow-up was fourteen years (range, two to thirty-one years). Preoperatively, the patients had been unable to perform self-care activities, such as grooming, feeding, and washing themselves, because of limited active external rotation or fixed internal rotation of the shoulder. All patients had decreased strength of the lateral rotator and abductor muscles and normal strength of the subscapularis and pectoralis major muscles. Radiographs showed some flattening of the humeral head, and four patients had posterior subluxation of the humeral head. A lateral rotational osteotomy of the proximal part of the humerus was performed between the insertions of the subscapularis and pectoralis major muscles. The site of the osteotomy was stabilized with catgut sutures in the periosteum in ten patients and with one or two staples in twelve. The extremity was immobilized in a plaster shoulder-spica cast for six weeks. At the latest follow-up evaluation, the average increase in active abduction was 27 degrees (range, 0 to 60 degrees) and the average increase in the arc of rotation was 25 degrees (range, 5 to 85 degrees). Supination of the forearm also had increased commensurate with the increase in external rotation. The appearance of the extremity had improved as well.     

Biomechanical evaluation of the medial collateral ligament of the elbow

Anatomical dissection and biomechanical testing were used to study twenty-eight cadaveric elbows in order to determine the role of the medial collateral ligament under valgus loading. The medial collateral ligament was composed of anterior, posterior, and occasionally transverse bundles. The anterior bundle was, in turn, composed of anterior and posterior bands that tightened in reciprocal fashion as the elbow was flexed and extended. Sequential cutting of the ligament was performed while rotation caused by valgus torque was measured. The anterior band of the anterior bundle was the primary restraint to valgus rotation at 30, 60, and 90 degrees of flexion and was a co-primary restraint at 120 degrees of flexion. The posterior band of the anterior bundle was a co-primary restraint at 120 degrees of flexion and a secondary restraint at 30 and 90 degrees of flexion. The posterior bundle was a secondary restraint at 30 degrees only. The reciprocal anterior and posterior bands have distinct biomechanical roles and theoretically may be injured separately. The anterior band was more vulnerable to valgus overload when the elbow was extended, whereas the posterior band was more vulnerable when the elbow was flexed. The posterior bundle was not vulnerable to valgus overload unless the anterior bundle was completely disrupted. The intact elbows rotated a mean of 3.6 degrees between the neutral position and the two-newton-meter valgus torque position. Cutting of the entire anterior bundle caused an additional 3.2 degrees of rotation at 90 degrees of flexion, where the effect was greatest. CLINICAL RELEVANCE: Physical findings in a patient who has an injury of the anterior bundle may be subtle, and an examination should be performed with the elbow in 90 degrees of flexion for greatest sensitivity. As the anterior bundle is the major restraint to valgus rotation, reconstructive procedures should focus on anatomical reproduction of that structure. Parallel limbs of tendon graft placed from the inferior aspect of the medial epicondyle to the area of the sublimis tubercle will simulate the reciprocal bands of the anterior bundle. Temporary immobilization with the elbow in flexion may relax the critically important anterior band of the reconstruction during healing.