E-poster 02: Basal Joint Arthroplasty Decreases Carpal Tunnel Pressure Category: Treatment Keyword: Hand and Wrist, Diseases and Disorders N/A - Not a clinical study ● Kevin Lutsky, MD ♦ ASIF ILYAS, MD ♦ Jonas L Matzon, MD ♦ Pedro Beredjiklian, MD Hypothesis: There is a documented association between carpal tunnel syndrome (CTS) and thumb carpometacarpal (CMC) arthritis, and these conditions commonly coexist. We have observed that patients with who have previously undergone thumb basal joint arthroplasty (BJA) rarely develop CTS in the future. Our hypothesis is that the baseline pressure within the carpal tunnel in patients with CMC arthritis is higher than the general population, and that BJA decreases the pressure within the carpal tunnel. Methods: Fifteen patients (3 with co-existent CTS) undergoing BJA were enrolled in the study. The pressure within the carpal tunnel immediately before and after BJA was measured using a commercially available pressure monitor device (Stryker STIC, Kalamazoo, MI). In patients with concomitant CTS undergoing both BJA and carpal tunnel release (CTR), the pressure was measured after BJA but prior to release of the transverse carpal ligament. Results: The pressure within the carpal tunnel decreased in all patients. The mean pressure prior to BJA was 18.7 mmHg and decreased to 7.7 mmHg after BJA (p < .05). Patients with concomitant CTS had a mean pre-BJA pressure of 26.7 mmHg, which decreased to 6.0 mmHg after BJA (p < .05). Summary Points: Patients with thumb CMC arthritis have a high baseline carpal tunnel pressure, which may in part explain the association between these conditions. BJA decompresses the carpal tunnel and decreases the pressure within. In patients with concomitant CTS, BJA alone decreases the carpal tunnel pressure. Further study is warranted on the need for discrete release of the transverse carpal ligament in patients undergoing BJA who have concomitant CTS. References: ● Consulting Fee: Synthes (Lutsky) ♦ No relevant financial relationships to disclose E-poster 03: axonal fusion in human digital nerves Category: Treatment, Surgical Technique Keyword: Hand and Wrist, Nerve Level 3 Evidence ♦ Ratnam Nookala, MBBS ♦ Wesley P Thayer, MD, PhD Hypothesis: We hypothesize that Polyethylene glycol (PEG) therapy enhances axonal injury recovery as demonstrated by electrophysiology and retrograde labelling in rats. We propose that this rapid nerve recovery will translate to clinical setting. Methods: To validate that PEG treatment results in early return of axonal continuity and function, retrograde tracing was performed in rats by exposing cut end of the repaired sciatic nerves to fast-blue tracer[1-4]. Experimental animals received PEG; control animals did not receive PEG. L2-L4 spinal cord segments were sectioned and fluorescent-labeled cells examined under microscope. Separately, in an IRB approved study, patients with traumatic lacerations involving digital nerves were treated with PEG after standard microsurgical neurorrhaphy. Sensory assessment was performed post operatively using static two-point discrimination (2PD) and Semmes-Weinstein monofilament (SWM) testing. The level of sensory function was determined by Medical Research Council Classification (MRCC) for Sensory Recovery-Scale. In a separate IRB exempt study, 2PD and MRCC score of 6 patients treated with standard microsurgical neurorrhaphy was collected. This data was compared with that of patients with PEG fused nerves. Results: PEG greatly improved neuronal labelling by retrograde tracers uptake in experimental vs negative control rats. The statistical analysis on retrograde labelled cells was performed by paired student t-test for PEG vs positive and negative controls (P value for negative control vs PEG group of 0.0363). PEG therapy has shown to improve functional outcomes and speed of nerve recovery in clinical setting. PEG was performed in four digital nerves in two patients. At 1wk, 10 mm 2PD was observed. SWM testing was 4.31. These results correlate with MRCC score of S3+ at 1wk after injury. Statistical analysis was performed between the PEG vs No peg nerve repairs using Mann Whitney Test. There was statistical significance between the PEG fused nerves and nerves fused with standard microsurgical repair without PEG (P values 0.0251, 0.0109, 0.0094 at 1, 4 and 8 weeks respectively). Summary Points: • In animals models Polyethylene glycol (PEG) therapy has shown to improve both physiologic and behavioral outcomes after nerve severance as evidenced by retrograde labelling. This is believed to be due to fusion of a fraction of the proximal axons to the distal axon stumps. • PEG therapy improves early functional outcomes after digital nerve injury in humans. • If this technique can successfully rescue distal axons after more proximal mixed-nerve injuries, we may be able to dramatically improve long-term recovery for a group of patients who typically have poor outcomes. References: Reference 1: Badia, J., et al., Topographical distribution of motor fascicles in the sciatic-tibial nerve of the rat. Muscle Nerve, 2010. 42(2): p. 192-201. Reference 2: Haase, P. and J.N. Payne, Comparison of the efficiencies of true blue and diamidino yellow as retrograde tracers in the peripheral motor system. J Neurosci Methods, 1990. 35(2): p. 175-83. Reference 3: Hayashi, A., et al., Retrograde labeling in peripheral nerve research: it is not all black and white. J Reconstr Microsurg, 2007. 23(7): p. 381-9. Reference 4: Novikova, L., L. Novikov, and J.O. Kellerth, Persistent neuronal labeling by retrograde fluorescent tracers: a comparison between Fast Blue, Fluoro-Gold and various dextran conjugates. J Neurosci Methods, 1997. 74(1): p. 9-15. Fluorescent retrograde labeled spinal motor neurons Figure 1: Graph showing no. of spinal motor neurons in controls vs PEG. The fluorescent labeled cells are counted in every 10th section of L2-L4 segments of the spinal cord. The PEG therapy groups demonstrated statistical significance (P<0.005) compared with negative control group. n=3 in each group. Post Op functional recovery in PEG vs Control patients Figure 2: Recovery after PEG fusion of digital nerves in patient 1 and 2 at post op follow ups. PEG fusion significantly improves recovery and functional outcomes as early as 1 week. ♦ No relevant financial relationships to disclose E-poster 04: PROSTHETIC REPLACEMENT OF THE WRIST Category: Treatment Keyword: Hand and Wrist Level 3 Evidence ♦ Sandra P. Fanner, MD Hypothesis: Current indications for total wrist arthroplasty include patients with symptomatic end stage post- traumatic wrist arthritis, rheumatoid arthritis, PRC failures and Kienböck disease. Arthroplasty may have advantage over arthrodesis because of the ability to retain motion. The purpose of this study was to evaluate the mid-term clinical outcomes and complications of 2 different devices : Universal 2 (23 implants) and Re-motion (10 implants) total wrist arthroplasty. Methods: We report the results of a retrospective review of 29 total wrist prostheses implanted in 27 patients (2 bilateral). Patient’s satisfaction, the Visual Analog Pain score, ROM and the Disabilities of the Arm, Shoulder, and Hand questionnaires were evaluated. We reviewed radiographic parameters (stress shielding at radial component, osteolysis around the screws, radiolucency lines, bone resorption, implant loosening) and complications. Results: At a mean follow-up of 58 months, the DASH score was 36 (68 preop.). Mean pain scores improved from 8.75 to 1.6. The mean wrist flexion-extension arc was 75° (30° preop.). Radiographs revealed radiological evidence of aseptic implant loosening (subsidence of the carpal component) in 5 cases. Early complications occurred in one patient only, consisting in marginal skin necrosis. Late complications that led to secondary surgery occurred in 5 of 33 patients: in 2 cases a revision of the distal carpal component had to be performed, 2 cases were converted to a wrist Swanson silicon spacer, one resection of the ulnar head for pain on the ulnar side of the wrist. Summary Points: Total wrist arthroplasty performed for pancarpal arthritis represents a good alternative to arthrodesis; it is more appealing for the patient as it provides pain relief and retains joint motion. Recent anatomic prosthetic models can yield successful outcomes with low mid-term failure rates; is mandatory do not forget that it is a complex surgery, with high cost and the success of which depends on the correct indication. References: Reference 1: Herzberg G. et al “Remotion” Total Wrist Arthroplasty: Preliminary Results of a Prospective International Multicenter Study of 215 Cases J Wrist Surg. 2012 Aug;1(1):17-22. Reference 2: Anderson M., Adams BD Total wrist arthroplasty. Hand Clin 2005, 21 : 621-630 Reference 3: Strunk S. Bracker W. Wrist joint arthroplasty : Results after 41 prostheses. Handchir Mikrochir Plast Chir 2009 41 : 141-147 Reference 4: Angel Ferreres, MD et al. Universal Total Wrist Arthroplasty: Midterm Follow-Up Study J Hand Surg 2011;36A:967–973. Reference 5: Kemal R, Weiss AP ”Total wrist arthroplasy for the patient with non-rheumatoid arthritis” Reference 6: Adams BD Wrist arthroplasty:partial and total. Hand Clin 2013 Figure 1 Figure 2 ♦ No relevant financial relationships to disclose E-poster 05: Long-term Outcomes of Primary Repair of Chronic Thumb Ulnar Collateral Ligament Injuries Category: Evaluation/Diagnosis, Treatment, Surgical Technique, Historical Information, Prognosis/Outcomes Keyword: Hand and Wrist, Diseases