The Importance of Preserving the Radial Tuberosity During Distal Biceps Repair.

BACKGROUND: The radial tuberosity contributes to the biceps supination moment arm and the elbow flexion moment. The purpose of our study was to compare the impact of a cortical bone trough versus an anatomic repair on measurements of the forearm supination moment arm and elbow flexion force efficiency. Our hypothesis was that a trough repair would decrease the tuberosity height, the native biceps supination moment arm, and elbow flexion force efficiency compared with an anatomic repair. METHODS: The isometric supination moment arm and elbow flexion force efficiency were measured in ten matched pairs of cadaveric upper limbs. After testing, the geometry of the proximal aspect of the radius was reconstructed with use of stereophotogrammetry. All of the repair sites were three-dimensionally reconstructed to quantify the disturbance of the trough on native anatomy. The tuberosity distance was defined as the distance between the central axis of the radius and the centroid of the respective repair site. RESULTS: Specimens with a trough repair had a 27% lower supination moment arm at 60° of supination (p = 0.036). There were no differences found for pronation or neutral forearm positioning (p > 0.235). Flexion force efficiency was not significantly different between the trough and anatomic repair groups. The average tuberosity distance was 11.0 ± 2.1 mm for the anatomic repairs and 8.3 ± 1.4 mm for the trough repairs (p = 0.003). The percentage of distance lost due to the trough was 25%. Furthermore, the supination moment arm in the supinated position was significantly correlated with the tuberosity distance. CONCLUSIONS: The trough technique resulted in a significant decrease (p = 0.036) in the moment arm of a 60° supinated forearm and a significant reduction (p = 0.003) in radial tuberosity height. The loss of the supination moment arm was correlated with the decrease in tuberosity height, providing evidence that the radial protuberance acts as a mechanical cam. CLINICAL RELEVANCE: The anterior protuberance of the radial tuberosity functions as a supination cam; therefore, consideration should be given to preserve its topographical anatomy during a distal biceps repair.

Preliminary results of recurrent cubital tunnel syndrome treated with neurolysis and porcine extracellular matrix nerve wrap.

PURPOSE: To evaluate the clinical results of revision neurolysis and wrapping with porcine extracellular matrix (AxoGuard Nerve Protector, AxoGen Inc., Alachua, FL) for cubital tunnel syndrome after one previous surgical decompression. METHODS: Twelve patients with recurrent cubital tunnel syndrome were treated with decompression, porcine extracellular matrix nerve wrap, and minimal medial epicondylectomy (if not previously performed). The average follow-up period was 41 months (range, 24-61 mo). All patients had recurrent symptoms after having previously undergone one surgical decompression. The mean patient age was 45 years (range, 30-58 y). All patients were evaluated subjectively and objectively (pain, satisfaction, static 2-point discrimination, grip strength, and pinch strength). RESULTS: A significant improvement was demonstrated in postoperative pain levels (from 8.5 to 1.7), grip strength (from 41% to 86% of the unaffected side), and pinch strength (from 64% to 83% of the unaffected side). Static 2-point discrimination improved from an average 10.4 mm preoperatively to 7.6 mm postoperatively. Eleven of 12 patients demonstrated 2 mm or more improvement in 2-point discrimination postoperatively. There were no complications related to the use of the porcine extracellular matrix for nerve wrapping. CONCLUSIONS: This study found that secondary decompression combined with porcine extracellular matrix nerve wrapping was an effective and safe treatment for patients with recurrent cubital tunnel syndrome. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Tendon allograft interposition for failed distal ulnar resection: 2- to 14-year follow-up.

PURPOSE: To evaluate the mid- to long-term outcome of distal radioulnar interposition arthroplasty using an Achilles allograft for salvage of painful instability after distal ulnar resection. METHODS: Twenty-six patients with an average age of 43 years were treated with Achilles tendon allograft interposition for failed distal ulnar resection. The average follow-up period was 79 months (range, 25-174 mo). Patients had an average of 2 previous procedures. All patients were evaluated clinically and radiographically. At the final follow-up, pain level, satisfaction, forearm rotation, grip strength, and Mayo Modified Wrist Score were assessed. RESULTS: All clinical parameters demonstrated statistically significant improvement at the final follow-up. Mean patient pain scores improved from 8.1 to 1.3, and patient satisfaction scores improved by an average of 6.8 points. Preoperative and postoperative forearm rotation and grip strength measurements improved by an average of 28° in pronation, 41° in supination, and 72% in grip strength. The mean Mayo Modified Wrist Score improved from 42 to 85. Postoperative radiographs showed preservation of an adequate space between the distal radius and the resected distal ulna. No postoperative infections and no foreign body reactions relating to the allograft were observed. CONCLUSIONS: Interposition arthroplasty with an Achilles allograft was an effective salvage procedure for the treatment of failed distal ulnar resection, preventing impingement of the ulnar stump on the radius. This procedure potentially provides a safe and reliable treatment, especially for patients who may not be candidates for implant arthroplasty. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

The contracted elbow: is ulnar nerve release necessary?

BACKGROUND: Prophylactic release of the ulnar nerve in patients undergoing capsular release for severe elbow contractures has been recommended, although there are limited data to support this recommendation. Our hypothesis was that more severely limited preoperative flexion and extension would be associated with a higher incidence of postoperative ulnar nerve symptoms in patients undergoing capsular release. MATERIALS AND METHODS: We conducted a retrospective review of 164 consecutive patients who underwent open or arthroscopic elbow capsular release for stiffness between 2003 and 2010. The ulnar nerve was decompressed if the patient had preoperative ulnar nerve symptoms or a positive Tinel test. Preoperative and postoperative range of motion and incidence of ulnar nerve symptoms were recorded. RESULTS: The mean improvement in the arc of motion of was 36.7°. New-onset postoperative ulnar nerve symptoms developed in 7 of 87 patients (8.1%) who did not undergo ulnar nerve decompression; eventually, 5 of these patients with persistent symptoms underwent ulnar nerve decompression. The rate of developing postoperative symptoms was higher if patients had preoperative flexion ≤ 100° (15.2%) compared with those with preoperative flexion >100° (3.7%). There was no association between preoperative extension or gain in motion arc and postoperative symptoms. CONCLUSIONS: The overall rate of ulnar nerve symptoms after elbow contracture release was low if ulnar nerve decompression was performed in patients with preoperative symptoms or a positive Tinel test. There was a higher rate of ulnar nerve symptoms in patients with more severe contractures (≤ 100° of preoperative flexion), which did not reach statistical significance.

Ten-year retrospective study of delayed diagnosis of injury in pediatric trauma patients at a level II trauma center.

BACKGROUND: Published rates of delayed diagnosis of injury (DDI) in pediatric trauma vary from 1.0% to 18%. The purpose of this study was to determine the long-term trend of DDI over 10 years, to identify risk factors associated with DDI, and to elucidate patterns of DDI. METHODS: All patients aged 14 and younger who were admitted to Parkview Hospital for major trauma between January 1, 1997 and December 31, 2006 were included (1100 patients). Data were collected from a trauma registry that is maintained of all trauma admissions. RESULTS: A total of 47 delayed diagnoses of injury were found in 44 patients for a rate of 4.0%. Patients with a DDI were more likely to have been intubated in the emergency department, transported by air, have an Injury Severity Score greater than 15, and have a Glasgow Coma Scale below 8 (P < 0.05). Mean intensive care unit and overall length of stay was longer in the DDI group. Missed injuries resulted in a change in therapy in 80% of cases. There were 5 missed intra-abdominal injuries, 4 of which required surgery. Three injuries were discovered upon outpatient follow-up. There was a trend for more missed upper extremity injuries in older patients and missed lower extremity injuries in younger patients. CONCLUSIONS: The rate of missed injuries remained relatively constant over the past 10 years at our institution. More severely injured patients are more likely to have missed injuries. Special attention to the lower extremities of the younger trauma patient may be warranted.