Justin M. Brown

Nerve transfers in the forearm and hand.

In the forearm, vital and expendable functions have been identified, and tendon transfers use these conventions to maximize function and minimize disability. Using similar concepts, distal nerve transfers offer a reconstruction that often is superior to reconstruction accomplished by traditional grafting. The authors present nerve transfer options for restoring motor and sensory deficits within each nerve distribution on the forearm and hand.

Distal median to ulnar nerve transfers to restore ulnar motor and sensory function within the hand: technical nuances.

ULNAR NERVE INJURIES can be severely debilitating and result in weakness of wrist flexion, loss of hand intrinsic function, and ulnar-sided hand anesthesia. When these injuries produce a Sunderland fourth- or fifth-degree injury, surgical intervention is necessary for functional recovery. Traditional methods for restoring hand intrinsic function after ulnar nerve palsy include interposition nerve grafting for timely presentations or tendon transfers for either complex injuries or late presentations. Distal median to ulnar nerve transfer to restore ulnar intrinsic nerve muscle function was first performed in 1991. We continue to find it advantageous for recovery of ulnar intrinsic function in patients with proximal ulnar nerve injuries by significantly reducing denervation time and directing motor fibers into this critical motor distribution. Several case reports have been published discussing the concept behind this approach, but none have outlined the specific steps involved in this operation. As such, this article discusses our operative methodology behind the distal median to ulnar neurotization, which includes a Guyon canal release, identification of donor median and recipient ulnar nerve fascicular anatomy within the forearm, and an operative tutorial on proper technique for neurotization to restore both ulnar motor and sensory function. We present the technical nuances of the following nerve transfers to restore ulnar nerve function within the hand: anterior interosseous nerve to deep motor branch of ulnar nerve, third webspace sensory contribution of median nerve to volar sensory component of ulnar nerve, and end-to-side reinnervation of ulnar dorsal cutaneous to the remaining median sensory trunk.

Distal nerve transfers: A biology-based rationale

Peripheral nerve injuries can result in devastating numbness and paralysis. Surgical repair strategies have historically focused on restoring the original anatomy with interposition grafts. Distal nerve transfers are becoming a more common strategy in the repair of nerve deficits as these interventions can restore function in months as opposed to more than a year with nerve grafts. The changes that take place over time in the cell body, distal nerve, and target organ after axotomy can compromise the results of traditional graft placement and may at times be better addressed with the use of distal nerve transfers. A carefully devised nerve transfer offers restoration of function with minimal (if any) detectable deficits at the donor site. A new understanding of cortical plasticity along with patient reeducation allow for good return of strength and function after nerve transfer.

Median to radial nerve transfer to restore wrist and finger extension: technical nuances.

BACKGROUND Traditional methods for restoring finger and wrist extension following radial nerve palsy include interposition nerve grafting or tendon transfers. We have described the utilization of distal nerve transfers for the restoration of radial nerve function in the forearm. OBJECTIVE We review the neuroanatomy of the forearm and outline the steps required for the implementation of this transfer. METHODS AND RESULTS We use a step-by-step procedural outline and detailed photographs, line drawings, and video to describe the procedure. CONCLUSION This approach is technically feasible and is a reconstructive option for patients with this nerve deficit.

Scratch Collapse Test Localizes Osborne's Band as the Point of Maximal Nerve Compression in Cubital Tunnel Syndrome

The objective of this study is to demonstrate the utility of the scratch collapse test (SCT) in localizing the point of maximal compression in cubital tunnel syndrome. From January 1, 2004 to December 1, 2005, 64 adult patients with cubital tunnel syndrome were evaluated by a single surgeon. Cubital tunnel syndrome was diagnosed based upon symptoms of numbness, tingling, and/or pain in the ulnar nerve distribution or by the presence of weakness or wasting of the ulnar-innervated intrinsic hand muscles. All diagnoses were confirmed with electrodiagnostic studies. As part of the physical examination, the SCT was performed along three subdivided segments in the region of the cubital tunnel. Results of the SCT were recorded and correlated with intraoperative findings. Of the 64 patients evaluated, 44 had a positive SCT that was either more profound or solely present a few centimeters distal to the medial epicondyle in the region of Osborne’s band. All of these patients subsequently underwent anterior submuscular transposition and were found to have a tight compression point at Osborne’s band corresponding to their preoperative SCT. This study suggests that the scratch collapse test may be a reliable physical examination technique for localizing the point of maximal nerve compression in patients with cubital tunnel syndrome. That point, in this series, corresponded with Osborne’s band.

Reinnervation of Urethral and Anal Sphincters With Femoral Motor Nerve to Pudendal Nerve Transfer

Lower motor neuron damage to sacral roots or nerves can result in incontinence and a flaccid urinary bladder. We showed bladder reinnervation after transfer of coccygeal to sacral ventral roots, and genitofemoral nerves (L1, 2 origin) to pelvic nerves. This study assesses the feasibility of urethral and anal sphincter reinnervation using transfer of motor branches of the femoral nerve (L2–4 origin) to pudendal nerves (S1, 2 origin) that innervate the urethral and anal sphincters in a canine model.

Post-cervical decompression parsonage-turner syndrome represents a subset of C5 palsy: six cases and a review of the literature: case report.

BACKGROUND: Approximately 5% of cervical decompression cases are complicated by postoperative weakness. Parsonage-Turner syndrome (PTS) or neuralgic amyotrophy is known to be precipitated by surgery and unrelated to technical or structural issues. Our practice has seen a number of cases of PTS after cervical decompression surgery. In this case report, we discuss a series of such patients, highlighting the commonalities with the more frequently diagnosed C5 palsy. We conclude with our management algorithm. CLINICAL PRESENTATION: Six patients with post-cervical decompression PTS were referred to our institution during a 32-month period. All patients were examined physically, radiographically, and electromyographically and were followed for up to 2 years or until symptoms resolved. Conservative management was the rule, and surgical intervention, including nerve releases and nerve reconstruction, was undertaken in select circumstances. In the majority of patients (4 of 6 patients), pain management and physical therapy alone were used and achieved eventual resolution of pain and recovery of motor strength. The other 2 patients required adjunctive surgical procedures to maximize their outcomes. CONCLUSION: PTS accounts for a subset of patients experiencing postoperative weakness after cervical decompression operations. Although it is at times difficult to arrive at this diagnosis, an understanding of the history of PTS, among other causes of postoperative weakness, allows a structured approach to these patients. An evidence-based approach to management helps provide the best outcome for a given patient.

Neural reconstruction methods of restoring bladder function

During the past century, diverse studies have focused on the development of surgical strategies to restore function of a decentralized bladder after spinal cord or spinal root injury via repair of the original roots or by transferring new axonal sources. The techniques included end-to-end sacral root repairs, transfer of roots from other spinal segments to sacral roots, transfer of intercostal nerves to sacral roots, transfer of various somatic nerves to the pelvic or pudendal nerve, direct reinnervation of the detrusor muscle, or creation of an artificial reflex pathway between the skin and the bladder via the central nervous system. All of these surgical techniques have demonstrated specific strengths and limitations. The findings made to date already indicate appropriate patient populations for each procedure, but a comprehensive assessment of the effectiveness of each technique to restore urinary function after bladder decentralization is required to guide future research and potential clinical application.

Reconstruction of Posterior Interosseous Nerve Injury Following Biceps Tendon Repair: Case Report and Cadaveric Study

Surgical repair of distal biceps tendon rupture is a technically challenging procedure that has the potential for devastating and permanently disabling complications. We report two cases of posterior interosseous nerve (PIN) injury following successful biceps tendon repair utilizing both the single-incision and two-incision approaches. We also describe our technique of posterior interosseous nerve repair using a medial antebrachial cutaneous nerve graft (MABC) and a new approach to the terminal branches of the posterior interosseous nerve that makes this reconstruction possible. Finally, we advocate consideration for identification of the posterior interosseous nerve prior to reattachment of the biceps tendon to the radial tuberosity.

Altered ulnar nerve kinematic behavior in a cadaver model of entrapment.

BACKGROUND Ulnar nerve entrapment at the elbow is more than a compressive lesion of the nerve. The tensile biomechanical consequences of entrapment are currently marginally understood. OBJECTIVE To evaluate the effects of tethering on the kinematics of the ulnar nerve as a model of entrapment neuropathy. METHODS The ulnar nerve was exposed in 7 fresh cadaver arms, and markers were placed at 1-cm increments along the nerve, centered on the retrocondylar region. Baseline translation (pure sliding) and strain (stretch) were measured in response to progressively increasing tension produced by varying configurations of elbow flexion and wrist extension. Then the nerves were tethered by suturing to the cubital tunnel retinaculum and again exposed to progressively increasing tension from joint positioning. RESULTS In the native condition, for all joint configurations, the articular segment of the ulnar nerve exhibited greater strain than segments proximal and distal to the elbow, with a maximum strain of 28 ± 1% and translation of 11.6 ± 1.8 mm distally. Tethering the ulnar nerve suppressed translation, and the distal segment experienced strains that were more than 50% greater than its maximum strain in an untethered state. CONCLUSION This work provides a framework for evaluating regional nerve kinematics. Suppressed translation due to tethering shifted the location of high strain from articular to more distal regions of the ulnar nerve. The authors hypothesize that deformation is thus shifted to a region of the nerve less accustomed to high strains, thereby contributing to the development of ulnar neuropathy.