O’Driscoll, Shawn W.

As there is evidence that ligamentous laxity is affected by the female hormones, we hypothesized that hormonal changes occurring during pregnancy could have a therapeutic role in preventing the development of a joint contracture. Knee joint contractures were created in pregnant and nonpregnant rats. After 2 wk of immobilization, the degree of contracture was measured with structural properties of the medial collateral and anterior cruciate ligaments and the pubic symphysis. Although not statistically significant, there was a general trend toward reduced contracture in pregnant compared with nonpregnant rats. Cutting the posterior capsule significantly decreased contracture for both the pregnant and nonpregnant groups, confirming the contribution of capsular structures to contracture. Ultimate loads of the medial collateral and anterior cruciate ligaments significantly decreased after immobilization compared with control, but there was no significant effect due to pregnancy. Stiffness and ultimate load of the pubic symphysis were not significantly different between pregnant and nonpregnant groups. The trend toward reduced contracture with pregnancy points toward a possible therapeutic role for female hormones in the prevention of postoperative and/or posttraumatic joint contracture.

Background: Little information exists regarding delayed-onset ulnar neuritis (DOUN) after arthroscopic release of elbow contractures. Purpose: To describe, in a large cohort of patients, the clinical presentation of and risk factors for developing DOUN after arthroscopic release of elbow contractures. Study Design: Case-control study; Level of evidence, 3. Methods: A retrospective study of 565 consecutive arthroscopic releases of elbow contractures was conducted. Essentially, DOUN was defined as ulnar neuritis or neuropathy, or worsening of pre-existing ulnar nerve symptoms, that developed postoperatively in patients with normal neurological examination findings immediately after surgery. After inclusion and exclusion criteria were met, 235 contracture releases in patients who had not undergone any ulnar nerve surgery remained and were used for the analysis of risk factors with a multivariate logistic regression analysis. Results: Twenty-six patients (11%) developed DOUN. The patients fell into 1 of 3 distinct groups. Fifteen (58%) presented with rapidly progressive DOUN, characterized by rapidly progressive sensorimotor ulnar neuropathy, increasing pain at the cubital tunnel during end-range flexion and/or extension, and rapidly deteriorating range of motion within the first week after surgery. Urgent ulnar subcutaneous nerve transposition was performed within 1 or 2 days of diagnosis. Eight (31%) presented with nonprogressive DOUN, characterized by mild sensory ulnar neuropathy, neither motor weakness nor substantial pain at the cubital tunnel, or loss of motion. Three (12%) presented with slowly progressive DOUN, characterized by the insidious onset of mild ulnar neuropathy. Significant risk factors for DOUN included a diagnosis of heterotopic ossification (odds ratio, 31; 95% CI, 5-191; P < .001), preoperative neurological symptoms (odds ratio, 6; 95% CI, 2-19; P = .001), and preoperative arc of motion (odds ratio, 0.97 per degree of motion; 95% CI, 0.96-0.99; P = .02). Conclusion: Delayed-onset ulnar neuritis is an important complication of arthroscopic release of elbow contractures. We recommend a high index of suspicion and monitoring patients with progressive loss of elbow motion and end-range pain for evidence of subclinical ulnar neuritis.

Purpose The purposes of this study were to determine whether delayed‐onset ulnar neuritis (DOUN) after elbow contracture release can be prevented and to compare the efficacy of ulnar nerve decompression versus subcutaneous transposition. Methods A retrospective study of 563 consecutive arthroscopic elbow contracture releases was conducted. The prophylactic efficacy of (1) subcutaneous transposition, (2) ulnar nerve decompression, (3) limited ulnar nerve decompression (7 to 8 cm), and (4) mini‐decompression (4 to 6 cm) was assessed prospectively. The efficacy of prophylactic strategies (transposition, decompression, limited decompression, or mini‐decompression) in preventing DOUN was compared by univariate survival analysis. Patients who underwent a subcutaneous transposition were matched with patients who underwent a standard open decompression or a limited decompression, according to gender, age (±10 years), diagnosis, and preoperative motion. This analysis was repeated after we excluded the patients who underwent associated open procedures (e.g., hardware removal). Results DOUN occurred in 26 of 235 patients (11%) who did not undergo any prophylactic procedure versus 8 of 295 patients (3%) who underwent a prophylactic ulnar nerve decompression or transposition at the time of contracture release ( P < .001). The neurologic impairment was significantly less severe after prophylactic decompression compared with patients without any prophylactic intervention (grade on Neuropathy Grading Scale, 2 v 4; P = .03). Ulnar nerve transposition and decompression were equally protective. The decompression length was the only factor significantly related to the failure of the prophylactic intervention (odds ratio, 0.19; P = .02). A mini‐decompression was not as effective as a prophylactic procedure, whereas a limited decompression was equal to a standard decompression. The case‐control analysis showed that the decompression and transposition had equal preventive effects but the transposition was associated with a higher rate of wound complications (19% v 4%, P = .03). Conclusions DOUN is a complication of arthroscopic elbow contracture release. Its incidence and severity can be reduced by limited open ulnar nerve decompression or transposition. Level of Evidence Level II, prospective comparative study with retrospective analysis.

AbstractPurposeTo test the hypothesis that visual estimation by a trained observer is as accurate and reliable as clinical goniometry for measuring elbow range of motion.MethodsInstrument validity and inter‐observer reliability of visual estimation was evaluated on a consecutive series of 50 elbow contractures. Four observers with different levels of elbow experience first estimated extension and flexion of the contracted elbows and then measured them with a blinded goniometer.ResultsInstrument validity for visually‐based goniometry was extremely high. ICC scores were 0.97 for both extension and flexion estimations. Systematic error was negligible (1°) with upper limits of agreement being 9° (95% CI: 7°–11°) and 8° (95% CI: 6°–10°), respectively, for extension and flexion. For the expert surgeon, 92% of the visual estimates were within 5° of the value obtained by clinical goniometry. Between experienced observers (elbow surgeon and physician assistant), the ICC’s were very high—0.96 for extension and 0.93 for flexion. The systematic errors were low, from −1° to 1° with upper limit of agreement being 11° (95% CI: 8°–14°). However, agreement was poor between an inexperienced study coordinator and the others (ICC’s: 0.51–0.38, systematic errors: 8°–18°, upper limit of agreement: 32°–40°). The accuracy of the visual estimations made by the experienced elbow surgeon was as good as the measurements taken with a goniometer by the physician assistant or the clinical fellow and better than those taken by an inexperienced study coordinator.ConclusionsThe trained human eye is highly capable of accurately estimating the range of motion of the elbow, compared to conventional clinical goniometry, depending on the experience of the observer.Level of evidenceDiagnostic study, Level II.

Background Although most people can lead near-normal lives with a limited but functional arc of elbow motion, athletes may find loss of terminal extension severely impairing. Hypothesis Arthroscopic contracture release is effective in restoring full elbow extension in athletes whose loss of terminal extension impairs their intensities and/or levels of performance in sport. Study design Case series; Level of evidence, 4. Methods Between 1997 and 2007, 24 athletes (26 elbows; mean age, 38 years [range, 12-58]) whose chief complaint was limited elbow extension (≤35°) underwent arthroscopic release of contractures (average follow-up, 33 months [range, 12-88]). All the patients were classified according to a sport-specific scoring system using the subjective patient outcome for return to sports score and the summary outcome determination score. Results All 26 elbows improved subjectively and objectively with surgery. Of the 26 elbows, 25 were rated by the patients as normal (n = 15) or near-normal (n = 10) at final follow-up. Pain during intense sporting activities was absent in 17, mild and occasional without affecting performance in 6, and severe enough to affect performance in 1. Of the 24 patients (26 elbows), 22 patients (23 elbows) returned to the same sport at the same level of intensity and performance as before injury. Two patients (3 elbows) returned to the same sport but failed to reach their preinjury levels of performance. Extension improved in all patients, with the average flexion contracture decreasing from 27° ± 7° (range, 10°-35°) to 6° ± 9° (range, 10° of hyperextension to 25°; P < .001). Lack of extension was not a residual impairment factor in any patients. Three patients developed delayed-onset ulnar neuropathy after surgery, 2 of which were treated by subcutaneous transposition. All 3 resolved completely, 2 within the first 6 weeks; the other took longer than a year. Conclusion The arthroscopic release of contractures is a predictable technique to achieve a highly functional elbow in athletes.

Purpose The purpose of this study was to document management strategies and complications relating to the use of anteromedial portals for elbow arthroscopy in a series of patients with subluxating or previously transposed ulnar nerves. Methods A review of 913 elbow arthroscopies showed that 59 elbows with a subluxating or previously transposed ulnar nerve required anterior compartment arthroscopic surgery. The patients with subluxating nerves had proximal anteromedial portals established by reducing and holding the nerve behind the epicondyle with a thumb while establishing or entering the portal. In cases of prior nerve transposition, the following techniques were used if, by palpation, localization of the ulnar nerve was considered to be (1) unequivocal, (2) equivocal, or (3) impossible: In group 1 (unequivocal) the proximal anteromedial portal was established in the normal antegrade fashion. In group 2 (equivocal) a 1‐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. In group 3 (impossible) a 2‐ to 4‐cm skin incision was made and the nerve was identified before placement of the portal. Results We found that 59 elbows in 56 patients had a subluxating ulnar nerve (31 elbows) or previous ulnar nerve transposition (28 elbows). The transposition had been subcutaneous in 21 and submuscular in 7. The proximal anteromedial portal was used in all but 3 cases (2 patients) of submuscular transposition that were early in the series. In those cases only 2 lateral portals were used for anterior compartment surgery. There were no operative ulnar nerve injuries related to the use of the proximal anteromedial portal. Conclusions Neither elbow arthroscopy nor specifically the use of the proximal anteromedial portal is contraindicated in patients with prior transposition or subluxation of the ulnar nerve. The management of the nerve can be based on the degree of certainty with which the nerve can be localized by palpation in the region of the planned portal. Level of Evidence Level IV, therapeutic case series.

AbstractAlthough silicone radial head arthroplasty has been successful in many patients, it has been associated with complications such as fractures of the prosthesis and silicone synovitis. Synovectomy and removal of the failed silicone radial head, with or without reimplantation of a metallic radial head, is indicated in such complications. In an effort to perform minimally invasive surgery, we performed arthroscopic removal of the silicone head combined with synovectomy in a series of such patients. The silicone prostheses were cut into two or three pieces and then removed. After a median follow up of 26 months, all patients reported excellent pain relief and there were no residual loose bodies. Removal of a failed silicone radial head can be successfully performed arthroscopically. This arthroscopic technique has the advantage of being minimally invasive and can be combined with other procedures including capsulectomy, if necessary.

A custom computer-controlled rapid prototyping system was designed and developed in this research. This system for bio-manufacturing of polymer scaffolds included 3D motion control components, a nozzle, a pressure controller, and a temperature-controlled reservoir containing a biomaterial. Heating elements built into the reservoir melted the biomaterial. The pressure line attached to the reservoir provided a controllable force that extruded the polymer biomaterial through the nozzle and deposited the polymer biomaterial onto a platform to fabricate scaffolds. A low pressure (830 KPa) system was designed and fabricated to accommodate different temperatures, motion speeds, and viscosities of polymer biomaterials. The reservoir with the nozzle was mounted to servo motor-controlled linear x-y motion devices along with a third servo motor-controlled device that controlled the z-position of the platform. Poly(ε-caprolactone) [PCL] was used to fabricate scaffolds with designed structure that were used in cell and tissue regeneration studies. 3D computer-aided design (CAD) with Pro-Engineer and computational finite element analysis (FEA) programs with MSC_Patran and MSC_Marc were used to model scaffold designs with appropriate architecture and material selection. The CAD models were used in FEA to develop new methods for determining mechanical properties of tissue scaffolds of desired structure and geometry. FEA models were validated by mechanical testing and other published results. Technology developed in this research has potential for the advancement of bio-manufacturing, and design optimization of scaffolds for tissue engineering.

Background Complete biceps tendon avulsions are frequently missed on clinical examination, suggesting the need for a reliable diagnostic test. Hypothesis Complete distal biceps avulsions can be reliably detected with the Hook test. Study Design Cohort study (diagnosis); Level of evidence, 2. Methods The hook test was performed by a single surgeon in a cohort of 45 patients undergoing surgical exploration of the distal biceps tendon. While the patient actively supinates with the elbow flexed 90°, an intact hook test permits the examiner to hook his or her index finger under the intact biceps tendon from the lateral side. With an abnormal hook test, indicating distal avulsion, there is no cord-like structure under which the examiner may hook a finger. Results Thirty-three patients had an avulsion and 12 had a partial tear. The hook test was abnormal in 33 of 33 (100%) patients with complete biceps avulsions, and intact in 12 of 12 with partial detachments. However, it was painful in 9 of those 12. In the noninjured contralateral arms, which served as the normal control group, 45 of 45 (100%) had a normal hook test. Magnetic resonance imaging (MRI) diagnosed a complete tear in 11 of 12 patients with partial tears and in 11 of 13 with complete lesions. The sensitivity and specificity were both higher with the hook test (both 100%) than with MRI (92% and 85%, respectively). Conclusions The hook test is a highly sensitive and specific test for assessment of distal biceps tendon avulsions.