Fitzsimmons, James S

Aims The aim of this study was to evaluate two hypotheses. First, that disruption of posterior bundle of the medial collateral ligament (PMCL) has to occur for the elbow to subluxate in cases of posteromedial rotatory instability (PMRI) and second, that ulnohumeral contact pressures increase after disruption of the PMCL. Materials and Methods Six human cadaveric elbows were prepared on a custom-designed apparatus which allowed muscle loading and passive elbow motion under gravitational varus. Joint contact pressures were measured sequentially in the intact elbow (INTACT), followed by an anteromedial subtype two coronoid fracture (COR), a lateral collateral ligament (LCL) tear (COR + LCL), and a PMCL tear (COR + LCL + PMCL). Results There was no subluxation or joint incongruity in the INTACT, COR, and COR + LCL specimens. All specimens in the COR + LCL + PMCL group subluxated under gravity-varus loads. The mean articular contact pressure of the COR + LCL group was significantly higher than those in the INTACT and the COR groups. The mean articular contact pressure of the COR + LCL + PMCL group was significantly higher than that of the INTACT group, but not higher than that of the COR + LCL group. Conclusion In the presence of an anteromedial fracture and disruption of the LCL, the posterior bundle of the MCL has to be disrupted for gross subluxation of the elbow to occur. However, elevated joint contact pressures are seen after an anteromedial fracture and LCL disruption even in the absence of such subluxation. Cite this article: Bone Joint J 2018;100-B:1060–5.

Background: Joint incongruity in posteromedial rotatory instability (PMRI) has been theorized to determine early articular degenerative changes. Our hypothesis was that the articular contact area and contact pressure differ significantly between an intact elbow and an elbow affected by PMRI. Methods: Seven cadaveric elbows were tested under gravity varus stress using a custom-made machine designed to simulate muscle loads and allow passive elbow flexion (0° to 90°). The mean contact area and contact pressure data were collected and processed using the Tekscan sensor and software. After testing the intact specimen (intact elbow), a PMRI injury was simulated (PMRI elbow) and the specimen was tested again. Results: The PMRI elbows were characterized by initial joint subluxation and significantly elevated articular contact pressure. Both worsened, corresponding with a reduction in contact area, as the elbow was flexed from 0° until the joint subluxation and incongruity spontaneously reduced (at a mean [and standard error] of 60° ± 5° of flexion), at which point the mean contact pressure decreased from 870 ± 50 kPa (pre-reduction) to 440 ± 40 kPa (post-reduction) (p < 0.001) and the mean contact area increased from 80 ± 8 mm 2 to 150 ± 58 mm 2 (p < 0.001). This reduction of the subluxation was also followed by a shift of the contact area from the coronoid fracture edge toward the lower portion of the coronoid. At the flexion angle at which the PMRI elbows reduced, both the contact area and the contact pressure of the intact elbows differed significantly from those of the PMRI elbows, both before and after the elbow reduction (p < 0.001). Conclusions: The reduction in contact area and increased contact pressures due to joint subluxation and incongruity could explain the progressive arthritis seen in some elbows affected by PMRI. Clinical Relevance: This biomechanical study suggests that the early degenerative changes associated with PMRI reported in the literature could be subsequent to joint incongruity and an increase in contact pressure between the coronoid fracture surface and the trochlea.

We describe the intermediate results of lateral ligamentous repair or reconstruction for posterolateral rotatory instability of the elbow. Between 1986 and 1999, we performed 12 direct repairs and 33 ligament reconstructions with a tendon autograft. One patient was lost to follow-up and 44 were retrospectively studied at a mean of six years (2 to 15).Surgery restored stability in all except five patients. In two the elbow became stable after a second procedure. The mean post-operative Mayo elbow performance score was 85 points (60 to 100). The result was classified as excellent in 19, good in 13, fair in seven and poor in five patients. Thirty-eight patients (86%) were subjectively satisfied with the outcome of the operation. Better results were obtained in patients with a post-traumatic aetiology (p = 0.03), those with subjective symptoms of instability at presentation (p = 0.006) and those who had an augmented reconstruction using a tendon graft (p = 0.04).Reconstruction using a tendon graft seems to provide better results than ligament repair and the results do not seem to deteriorate with time. The outcome of this procedure is less predictable in patients with no subjective instability.

Objectives: To describe the surgical treatment and patient outcomes of chronic elbow dislocations. Design: Retrospective review. Setting: Two tertiary referral centers. Patients/Participants: All patients with surgically treated chronic elbow dislocation with no associated articular fracture from January 2009 to January 2015. Intervention: Review of patient demographics, injury chronicity, surgical technique, and patient outcomes. Main Outcome Measurement: Clinical outcomes included elbow range of motion and complications. Radiographic outcomes included the presence of heterotopic ossification. Patient-reported outcomes included the Mayo Elbow Performance Index (MEPI) and the Summary Outcome Determination (SOD). Results: Thirty-two patients with mean follow-up of 22 months (range, 13–41 months) were included. The mean dislocation duration was 6 months (range, 1–34 months). The mean preoperative range of motion was 8 degrees (range, 0–30 degrees). There were no infections or recurrent dislocations. One patient developed transient ulnar nerve palsy postoperatively. There were no cases of new or progressive heterotopic ossification. The mean postoperative extension was 31 degrees (range, 0–75 degrees), and the mean postoperative flexion was 132 degrees (range, 95–150 degrees); the mean final arc of motion was 101 degrees (range, 50–140 degrees). The mean postoperative MEPI was 93 (range, 70–100), and the mean SOD score was 9 (range, 6–10). Using the MEPI, 97% (31/32 patients) had good or excellent outcome. There was no difference in flexion/extension arc or MEPI scores between groups of elbows older and younger than 17 years or dislocations less or more than 3 months. Conclusion: This is the largest case series of surgically treated patients with chronic elbow dislocation. Using our surgical technique, 97% of patients had good or excellent outcome with a low complication rate. Open reduction of chronic elbow dislocation can be accomplished while permitting early motion with minimal recurrent dislocation risk. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Abstract Reconstruction of the lateral ulnar collateral ligament of the elbow is the primary treatment for recurrent symptomatic posterolateral rotatory instability. Although a number of lateral ulnar collateral ligament reconstruction techniques have been described, the docking technique has received general acceptance. In this technique, the graft is passed through a tunnel on the ulnar side and the 2 free limbs are docked into the humerus at the isometric point on the lateral condyle. Advantages of this method of reconstruction include reduced bone removal, decreased soft tissue damage, and precise control of graft tensioning. When precise surgical steps are followed, this technique can be performed in a reliable, efficient, and reproducible manner for patients with posterolateral rotatory instability of the elbow. Technique Video video See video under supplementary data.

Objectives To determine the ability to sonographically identify the posterior cutaneous nerve of the forearm (PCNF) and its distal epicondylar branches using sonographically guided perineural injections in an unembalmed cadaveric model. Methods A single experienced operator used a 12–3‐MHz linear array transducer to identify the PCNF and its distal epicondylar region branches in 10 unembalmed cadaveric specimens (6 right and 4 left) obtained from 10 donors. Sonographically guided perineural PCNF injections were then completed with a 22‐gauge, 38‐mm stainless steel needle to deliver 0.25 mL of 50% diluted colored latex at 3 points along the PCNF. The latex location was then confirmed via dissection. Results The 10 donors included 4 male and 6 female cadavers aged 48 to 94 years (mean, 73 years) with body mass indices of 19 to 37 kg/m 2 (mean, 26 kg/m 2 ). The operator sonographically identified the PCNF and several distal branches traversing over or directly adjacent to the lateral epicondyle in all 10 specimens. Only 7 of 10 specimens showed a distinct PCNF bifurcation into anterior and posterior divisions, and all 7 were accurately identified and localized on sonography. There was no evidence of latex overflow to clinically relevant adjacent structures or injury to regional vessels or nerves. Conclusions High‐resolution sonography can identify the PCNF and its distal epicondylar branches. Sonographic evaluation of the PCNF should be included in the evaluation of patients presenting with refractory or atypical lateral elbow pain syndromes. Diagnostic and therapeutic sonographically guided procedures targeting the PCNF or its lateral epicondylar branches are feasible and warrant further investigation.

Abstract Posterolateral rotatory instability (PLRI) is the most commonly encountered pattern of elbow instability. It is the result of disruption of the lateral collateral ligament complex leading to a posterolateral rotatory subluxation of the ulna and radial head. A number of examination maneuvers have been described to assist in clinical identification of PLRI. Despite this, some inconsistency in the description of these techniques remains in the orthopaedic literature. This Technical Note details the mechanism of injury and patient presentation, and emphasizes the primacy of the posterolateral rotatory drawer test in the assessment of PLRI while providing video instruction on how it should be performed. Technique Video video See video under supplementary data.

Abstract Currently, a number of examination and imaging techniques exist for diagnosing posterolateral rotatory instability of the elbow. Although the posterolateral rotatory drawer is the primary examination maneuver, other special tests include the lateral pivot‐shift test, prone push‐up test, chair push‐up test, and tabletop push‐up test. In addition, posterolateral rotatory instability can be evaluated using radiography, magnetic resonance imaging, dynamic fluoroscopy, or dynamic ultrasound. In this Technical Note, each of these tests is described in detail. Video instruction is also provided to further explain the techniques and provide examples of positive tests. Technique Video video See video under supplementary data.

ObjectivesWe sought to determine if a durable bilayer implant composed of trabecular metal with autologous periosteum on top would be suitable to reconstitute large osteochondral defects. This design would allow for secure implant fixation, subsequent integration and remodeling.Materials and MethodsAdult sheep were randomly assigned to one of three groups (n = 8/group): 1. trabecular metal/periosteal graft (TMPG), 2. trabecular metal (TM), 3. empty defect (ED). Cartilage and bone healing were assessed macroscopically, biochemically (type II collagen, sulfated glycosaminoglycan (sGAG) and double-stranded DNA (dsDNA) content) and histologically.ResultsAt 16 weeks post-operatively, histological scores amongst treatment groups were not statistically different (TMPG: overall 12.7, cartilage 8.6, bone 4.1; TM: overall 14.2, cartilage 9.5, bone 4.9; ED: overall 13.6, cartilage 9.1, bone 4.5). Metal scaffolds were incorporated into the surrounding bone, both in TM and TMPG. The sGAG yield was lower in the neo-cartilage regions compared with the articular cartilage (AC) controls (TMPG 20.8/AC 39.5, TM 25.6/AC 33.3, ED 32.2/AC 40.2 µg sGAG/1 mg respectively), with statistical significance being achieved for the TMPG group (p < 0.05). Hypercellularity of the neo-cartilage was found in TM and ED, as the dsDNA content was significantly higher (p < 0.05) compared with contralateral AC controls (TM 126.7/AC 71.1, ED 99.3/AC 62.8 ng dsDNA/1 mg). The highest type II collagen content was found in neo-cartilage after TM compared with TMPG and ED (TM 60%/TMPG 40%/ED 39%). Inter-treatment differences were not significant.ConclusionsTM is a highly suitable material for the reconstitution of osseous defects. TM enables excellent bony ingrowth and fast integration. However, combined with autologous periosteum, such a biocomposite failed to promote satisfactory neo-cartilage formation. Cite this article: E. H. Mrosek, H-W. Chung, J. S. Fitzsimmons, S. W. O’Driscoll, G. G. Reinholz, J. C. Schagemann. Porous tantalum biocomposites for osteochondral defect repair: A follow-up study in a sheep model. Bone Joint J 2016;5:403–411. DOI: 10.1302/2046-3758.59.BJR-2016-0070.R1.