Bachman, Daniel R.

Purpose To analyze the complications of arthroscopic heterotopic ossification (HO) excision and compare them with those of open removal of HO or a combined open‐arthroscopic approach. Methods We performed a retrospective review of elbow HO removal cases performed by a single surgeon from 1997 to 2014. In all cases studied, the intention was to restore range of motion owing to the presence of HO causing functional impairment. The arthroscopic, open, and combined treatment groups were compared. Results The study cohort consisted of 223 surgical procedures performed on 213 elbows in 211 patients. Fifty major complications occurred in 46 cases (21%): 17 hematomas (8%) treated by irrigation and debridement, 8 cases of HO requiring reoperation (4%), 7 deep infections (3%), 4 contractures (2%), 3 cases of delayed‐onset ulnar neuritis (1%), 2 cases of distal humeral avascular necrosis (1%), 2 tendon ruptures (1%), 2 cases of instability requiring reconstruction (1%), 2 postoperative fractures (1%), 1 intraoperative fracture (<0.5%), 1 case of worsening of pre‐existing neuropathic pain (<0.5%), and 1 permanent partial posterior interosseous nerve injury (<0.5%). Of these 46 cases, the major complications occurred in 6 of the 41 (15%) performed arthroscopically, in 36 of the 158 (23%) performed open and in 4 of the 21 (17%) with combined (i.e. open + arthroscopic) HO removal. Preventive strategies, introduced to prevent hematomas and delayed‐onset ulnar neuritis, reduced the rate of major complications from 35% during the period from 1997 to 2005 to 10% during the period from 2006 to 2014 ( P < .0001). Moreover, the rate of reoperations was reduced from 34% to 10% in the same periods ( P < .0001). Minor complications occurred in 36 cases (16%), including 17 cases of transient nerve palsy, 9 cases of superficial infection or delayed wound healing, 6 cases of mild instability, and 4 cases of hematoma resolved by aspiration. Conclusions The use of arthroscopy—or a combination of arthroscopic and open techniques—to remove HO around the elbow by a surgeon skilled in both arthroscopic and open elbow surgery does not increase the risk of major complications or need for reoperation compared with traditional open surgery. Preventive strategies, such as avoiding raising skin flaps by using multiple separate incisions for open and prophylactic ulnar nerve decompression in arthroscopic cases, were developed during the study period. These strategies were monitored prospectively and found to be effective in preventing two‐thirds of the major complications needing reoperation with both open and arthroscopic HO removal. Level of Evidence Level III, retrospective comparative study of prospectively collected data.

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.

Purpose To report the safety of using the proximal anteromedial portal, using a simplified ulnar nerve management strategy derived from an earlier study, in a series of patients with previously transposed ulnar nerves. Methods A retrospective review of all elbow arthroscopies performed by a single surgeon from 2009 to 2014 was performed. The following techniques were used if, by palpation, localization of the ulnar nerve was considered to be certain (group 1) or uncertain (group 2): In group 1 (certain) the proximal anteromedial portal was established in the normal antegrade fashion. In group 2 (uncertain) a 1‐ to 3‐cm incision was made at the planned proximal anteromedial portal site, and blunt dissection down to the capsule was performed without identification of the nerve. The nerve was not visualized but sometimes was palpated through the wound to confirm its location anteriorly or posteriorly. If there was a disparity between the prior operative records and the physical examination findings, the nerve was explored through a 3‐ to 4‐cm incision. Results We reviewed 394 elbow arthroscopy cases, 22 of which had a prior transposed ulnar nerve (21 subcutaneous and 1 submuscular) that required anterior‐compartment arthroscopic surgery. Group 1 (certain location) consisted of 9 elbows (41%), whereas group 2 (uncertain location) consisted of 13 (59%). In 2 cases in group 2, the ulnar nerve was explored because of the disparity between the previous medical records and the physical examination findings. There were no operative ulnar nerve injuries related to the use of the proximal anteromedial portal. Conclusions The proximal anteromedial portal was able to be used safely in patients with prior transposition of the ulnar nerve. This was achieved by using an algorithm based on the degree of certainty with which the nerve can be localized in the region of the planned portal by clinical palpation. Level of Evidence Level IV, therapeutic case series.