Selective Thumb Carpometacarpal Joint Denervation for Painful Arthritis: Clinical Outcomes and Cadaveric Study.

PURPOSE: To determine the innervation pattern to the thumb carpometacarpal (CMC) joint and assess the safety and efficacy of selective joint denervation for the treatment of pain and impairment associated with thumb CMC arthritis. METHODS: Cadaveric dissections were performed in 10 fresh upper extremities to better define the innervation patterns to the CMC joint and guide the surgical approach for CMC joint denervation. Histologic confirmation of candidate nerves was performed with hematoxylin and eosin staining. Results from a series of 12 patients with symptomatic thumb CMC arthritis who underwent selective denervation were retrospectively evaluated to determine the safety and efficacy of this treatment approach. Differences in preoperative and postoperative measurements of grip and key-pinch strength as well as subjective reporting of symptoms were compared. RESULTS: Nerve branches to the thumb CMC joint were found to arise from the lateral antebrachial cutaneous nerve (10 of 10 specimens), the palmar cutaneous branch of the median nerve (7 of 10 specimens), and the radial sensory nerve (4 of 10 specimens). With an average follow-up time of 15 months, 11 of 12 patients (92%) reported complete or near-complete relief of pain. Average improvements in grip and lateral key-pinch strength were 4.1 ± 3.0 kg (18% ± 12% from baseline) and 1.7 ± 0.5 kg (37% ± 11% from baseline), respectively. One patient experienced the onset of new pain consistent with a neuroma that resolved with steroid injection. All patients were released to light activity at 1 week after surgery, and all activity restrictions were lifted by 6 weeks after surgery. CONCLUSIONS: Selective denervation of the CMC joint is an effective approach to treat pain and alleviate impairment associated with CMC arthritis. The procedure is well tolerated, with faster recovery as compared with trapeziectomy. Branches arising from the lateral antebrachial cutaneous nerve, palmar cutaneous branch of the median nerve, and radial sensory nerve can be identified and resected with a single-incision Wagner approach. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Impact of high resolution 3 tesla MR neurography (MRN) on diagnostic thinking and therapeutic patient management.

OBJECTIVE: To evaluate the impact of magnetic resonance neurography (MRN) on diagnostic thinking and therapeutic choices in patients with suspected peripheral neuropathy. METHODS: IRB approval was obtained for this HIPAA-compliant study. Questionnaires were administered to six surgeons regarding the diagnosis and treatment in 85 patients suspected of having peripheral neuropathy, before (pretest) and after (posttest) MRN. Multiple outcome measures related to diagnostic confidence and surgical decision-making were assessed. RESULTS: The final cohort included 81 patients (30 men and 51 women, age 47 ± 17 years). The following changes were observed from pretest to posttest questionnaires: 23% in nerve involvement (P < 0.05), 48% in degree of confidence of nerve involvement (P < 0.01), 27% in grade of injury (P < 0.05), 33% in differential diagnosis (P < 0.05), 63% in degree of confidence in need for surgery (P < 0.001), 41% in timing of surgery (P < 0.01), 30% in approach to surgery (P < 0.05), 58% in degree of confidence in approach to surgery (P < 0.001), 30% in estimated length of surgery (P < 0.05) and 27% in length of incision (P < 0.05). The dichotomous decision regarding surgical or nonsurgical treatment changed from pro to con in 17%. CONCLUSION: MRN results significantly influenced the diagnostic thinking and therapeutic recommendations of peripheral nerve surgeons. KEY POINTS: • In patients with peripheral neuropathy, MRN significantly impacts diagnostic thinking. • In patients with peripheral neuropathy, MRN significantly impacts therapeutic choices. • 3-T MRN should be considered in presurgical planning of patients with peripheral neuropathy.

High-resolution MR neurography: evaluation before repeat tarsal tunnel surgery.

OBJECTIVE: The purpose of this study was to retrospectively determine the accuracy of high-resolution MR neurography (MRN) in presurgical evaluation before repeat tarsal tunnel surgery. MATERIALS AND METHODS: Ten MRN studies of nine patients (one man, eight women; mean age, 44.4 years; range, 23-67 years) who had been referred to a peripheral nerve specialist because of persistent symptoms after tarsal tunnel release were reviewed. The MRN findings studied included presence and location of focal fibrosis, presence or absence of nerve abnormality, location of nerve abnormality, and presence of neuroma formation and regional muscle denervation. The diagnostic accuracy of MRN in detection of posterior tibial nerve, medial plantar nerve, and lateral plantar nerve injury was calculated with clinical and intraoperative findings as the reference standards. RESULTS: Nine of 10 MRN studies (90%) had findings of nerve reentrapment related to focal fibrosis. Injured nerves were reliably visualized with MRN in all patients. MRN had a sensitivity of 77% for posterior tibial nerve, 100% for medial plantar nerve, and 100% for lateral plantar nerve injury, and the overall accuracy was 86%. The sensitivity of MRN was 91% for the presence of focal fibrosis affecting the three nerves and 67% for neuroma detection. Regional muscle denervation was better evaluated on MRN studies than at surgery. Smaller (1-3 mm) abnormal cutaneous nerve branches were better seen at surgery. CONCLUSION: MRN yields accurate morphologic information about the location and extent of nerve injury after failed tarsal tunnel release and facilitates preoperative diagnosis.

MR neurography findings of soleal sling entrapment.

OBJECTIVE: The ever-increasing use of higher field strength (3 T) scanners and novel pulse sequences with improved spatial resolution and signal-to-noise ratio have rendered MR neurography (MRN) a valuable technique in the assessment of peripheral neuropathies. The aim of this study is to illustrate the imaging findings of high-resolution MRN in patients who suffer from tibial nerve entrapment due to a soleal fibromuscular sling and to correlate the imaging findings with intraoperative and clinical examination results. CONCLUSION: This article depicts the surgically confirmed imaging findings of high-resolution MRN in tibial nerve entrapment by the soleal sling.