Kai Megerle

Is Nerve Regeneration after Reconstruction with Collagen Nerve Conduits Terminated after 12 months? The Long-Term Follow-Up of Two Prospective Clinical Studies

BACKGROUND Long-term follow-up data of digital nerve reconstructions with nerve conduits are limited. Furthermore, it is not known whether nerve regeneration after tubulization is terminated after 12 months, or whether improvement can be expected after this period of time. Therefore, we present the long-term follow-up of two prospective clinical trials. PATIENTS AND METHODS We invited 45 patients who were enrolled in two prospective clinical trials for long-term follow-up. All patients underwent digital nerve reconstruction with conduits made from bovine collagen I due to a gap length of < 26 mm. Sensibility was assessed using static and moving two-point discrimination and monofilament testing. Follow-up data of 1 week, 3, 6, and 12 months, and the current examination were available. Improvement of sensibility was investigated by comparison of the American Society for Surgery of the Hand classification score at 12-month follow-up with the score raised at current examination. RESULTS We examined 20 reconstructed nerves in 16 patients with a mean follow-up of 58.1 months (range, 29.3-93.3 months). We found an improved sensibility at current follow-up compared with the 12-month follow-up in 13 cases. Three cases had the same values whereas four cases had worsened sensibility. Improvement of sensibility was associated with a significantly shorter nerve gap length with significantly better results if the gap length was < 10 mm. CONCLUSION Our results provide evidence that the long-term recovery of sensibility after digital nerve tubulization depends on the nerve gap length with better results in those < 10 mm. Nerve regeneration after tubulization seems not to be terminated after 12 months.

The normal sensibility of the hand declines with age – a proclamation for the use of delta two-point discrimination values for sensibility assessment after nerve reconstruction

The scores used to evaluate sensibility after digital nerve reconstruction do not take the patients age into consideration, although there is evidence that the outcome after digital nerve reconstruction is age‐dependent. However, it is not clear if the normal sensibility of the hand is also age‐dependent, as the existing studies have major limitations. We evaluated the normal sensibility of the hand in 232 patients using static and moving two‐point discrimination (2PD) tests and the Semmes–Weinstein‐monofilament test. We found the climax of sensibility in the third decade with age‐dependent deterioration afterwards in all three tests. Mean 2PD values of the radial digital nerve of the index finger (N3) showed to be significantly lower than values of the ulnar digital nerve of the small finger (N10). To overcome shortcomings of classification systems that do not consider the patients age and inter‐individual differences, we suggest using the difference of the static 2PD values of the injured to the uninjured contralateral nerve (delta 2PD) for assessment of sensibility after digital nerve reconstruction.

Median neuropathy in malunited fractures of the distal radius

PurposeIrritation of the median nerve is a well-characterized complication after acute fractures of the distal radius, but there is limited literature on median neuropathy in malunited fractures. The aims of our prospective study were to estimate the prevalence of the median neuropathy, explore the relationship between radiographic findings and the condition, and investigate whether corrective osteotomy without carpal tunnel release was a sufficient treatment.MethodsThirty consecutive patients, who were referred to us for treatment of symptomatic distal radial malunion, underwent nerve conduction studies of both wrists by one board-certified neurologist under standardized conditions. Test results were correlated with conventional radiographic parameters (radial tilt, radial inclination, palmar shift, ulnar variance, radiolunate and capitolunate angle) and computer tomography (CT) based measurements of the cross-sectional area of the carpal tunnel. After corrective osteotomy without carpal tunnel release, 10 of 13 patients with unilateral preoperative median neuropathy agreed to an electrodiagnostic re-examination by the same neurologist.ResultsNineteen patients demonstrated abnormal test results, but only seven patients complained about paresthesias of median-innervated fingers. There was no correlation between median neuropathy and conventional radiographic parameters. Surprisingly, the cross-sectional area of the carpal canal was significantly greater for patients with median neuropathy. Symptoms resolved in all patients after corrective osteotomy. Postoperatively, six of ten patients demonstrated improved nerve conduction studies, although only four patients demonstrated normal test results.DiscussionThere is a high rate of subclinical median neuropathy in malunited distal radial fractures that cannot be predicted by conventional radiographic parameters. Corrective osteotomy without carpal tunnel release is a sufficient treatment for neuropathy in malunited distal radius fractures.

Microsurgeons do better –Tactile training might prevent the age‐dependent decline of the sensibility of the hand

Recent data demonstrate that the normal sensibility of the hand seems to be age‐dependent with the best values in the third decade and a consecutive deterioration afterwards. However, it is not clear if long‐term tactile training might prevent this age‐dependent decline. We evaluated sensibility of the hand in 125 surgeons aged between 26 and 75 years who perform microsurgical operations, thereby undergoing regular tactile training. We examined sensibility of the radial digital nerve of the index finger (N3) and the ulnar digital nerve of the small finger (N10) using static and moving two‐point discrimination (2PD) tests and compared the results to 154 age‐matched individuals without specific long‐term tactile training. We found significantly lower static and moving 2PD values for the sixth, seventh, and eighth decade of life in the microsurgery group compared to the control group (p < 0.05). This study demonstrates that long‐term tactile training might prevent the known age‐dependent decline of the sensibility of the hand.

Impact of Timing of Admission and Microvascular Reconstruction on Free Flap Success Rates in Traumatic Upper Extremity Defects.

BACKGROUND Despite a growing body of knowledge, the timing of microsurgical reconstruction for the upper extremity remains a controversial topic. Most of the available literature deals with lower extremity reconstruction and the few reports on microsurgical reconstruction of the upper extremity are mostly concerned with infection rates and rarely consider thrombosis and changes in coagulation parameters. METHODS We performed a retrospective review of all free flaps performed for upper extremity reconstruction at our institution from 2000 to 2010. Only acute, isolated traumatic defects of the upper extremity requiring a free flap for reconstruction were included in this study. A review of medical records was performed to assess, among others, comorbidities, timing of reconstruction, and platelet levels. RESULTS A total of 41 patients were included in this study, 70% of whom were male. Mean age at the time of surgery was 40.8 ± 15.4 years. Patients who were directly referred to our hospital underwent reconstruction significantly faster than those who were transferred secondarily (p = 0.0001). The number of surgical revisions as well as the flap loss rate was higher in patients undergoing reconstruction more than 1 week after trauma (p = 0.09 and 0.033, respectively). A significantly higher platelet count was seen in the patients undergoing delayed reconstruction (p = 0.002). CONCLUSION In our study, early microsurgical reconstruction of the upper extremity yielded better results in terms of lower rates of surgical revisions and flap loss. This might be partly because of a trauma-induced thrombocythemia, with a maximum level of platelets in the 2nd week post trauma. We, therefore, advocate a timely coverage of these defects along with an anticoagulatory regimen including some form of platelet inhibition.

Treatment of Ulnar Impaction Syndrome with and without Central TFC Lesion

Background Arthroscopic debridement of the triangular fibrocartilage (TFC) is well accepted in patients with ulnar impaction syndrome with central TFC lesions. Treatment remains controversial, however, when there is no such lesion from radiocarpal view. Purpose This study assessed the clinical outcome of arthroscopic central TFC resection and debridement and secondary ulnar shortening in patients with ulnar impaction with central TFC lesion compared with patients without TFC lesion. Patients and Methods Thirty‐two consecutive patients with ulnar impaction syndrome were arthroscopically treated, 16 of whom had a central lesion of the TFC that was debrided. In the 16 patients with no lesion from the radiocarpal view, the TFC was centrally resected and debrided to decompress the ulnocarpal joint. Persisting symptoms necessitated ulnar shortening in four patients in each group. Two patients underwent repeat arthroscopic TFC debridement. All patients were examined at 3, 6, and 12 months, and at final follow‐up (mean: 1.7 years) following arthroscopy, respectively ulnar shortening or hardware removal. Results In both groups, pain, Krimmer, and DASH scores significantly improved. Improvements of DASH scores were significantly higher in patients without lesion at 12 months and at final follow‐up. For other parameters, no significant difference was found between the two groups. Conclusion In both situations, with and without central TFC lesion, resection and debridement sufficiently reduced the ulnar‐sided wrist pain and improved function in three out of four patients, and therefore qualified as the first‐line treatment of ulnar impaction syndrome as arthroscopy is performed, anyway. Those patients who complained of persisting or recurrent ulnar‐sided wrist pain finally benefitted from ulnar shortening osteotomy as the secondary procedure. Level of Evidence Therapeutic III, case‐control study.

Primär adaptierende vs. sekundäre Wundverschlüsse bei Infektionen der Hand – Unterschiede und Vorteile

BACKGROUND Hand infections are common surgical emergencies. There are still controversial opinions regarding the ideal timing of wound closure after radical débridement of the infection. The aim of this retrospective study was to compare the outcome of primary adaptive and secondary wound closures after operative débridement in patients with hand infections. METHODS We retrospectively analysed all infections of the hand treated operatively in our hospital in the years 2011 and 2012 with a follow-up of at least 6 months. We included 16 patients with primary adaptive wound closure (PWC) and 12 patients with secondary wound closure (SWC) in this study. The evaluated parameters were the need for re-operations, the length of hospital stay, the overall satisfaction with the treatment, the characteristics of the scar and the mobility of the hand. RESULTS No patient had to be re-operated after PWC or SWC, respectively. Patients in the PWC group were kept significantly shorter as inpatients in comparison to patients in the SWC group (3.0 days vs. 5.1 days; p=0.048). Overall patient satisfaction with the treatment and the scar was comparable for both groups, as was the re-establishment of the mobility of the treated hand to preoperative levels. CONCLUSION This study shows that wounds after radical débridement for infection of the hand can be closed primarily adaptive without disadvantages for the patient. The length of hospitalisation is significantly shorter if the wound is closed primarily adaptive, a fact that is important for patient comfort and the socio-economic system. Both, primary adaptive and secondary wound closures generally have good outcomes with possible advantages for primary adaptive wound closures concerning the characteristics of the scar.

Biomechanik und Behandlung der karpalen Instabilität

Die Biomechanik der Handwurzel (Karpus) ist komplex und nach wie vor zu großen Teilen unklar. Mehrere biomechanische Modellvorstellungen existieren, bilden die Wirklichkeit aber nach wie vor unzureichend ab. Unter dem Begriff „karpale Instabilität“ werden dabei Phänomene zusammengefasst, bei denen knöcherne und ligamentäre Verletzungen der Handwurzel im Laufe von Jahren bis Jahrzehnten zu arthrotischen Verschleißerscheinungen der Handwurzel führen.

Persistierende Beschwerden nach Karpaldachspaltung: die Schwierigkeit der präoperativen Planung – ein Fallbericht

Die Revisionsrate nach Karpaldachspaltungen wird in der Literatur zwischen 3-19% angegeben 1 2 . Dabei wird ein Rezidiv als das erneute Auftreten von Beschwerden nach 6 beschwerdefreien Monaten definiert und ist durch eine Verlangerung der Nervenleitgeschwindigkeit nachweisbar 3 . In vielen Fallen ist das Beschwerdebild jedoch weniger eindeutig und eine Abgrenzung mit exakter Diagnostik schwierig. Das echte Rezidiv ist von persistierenden Beschwerden in der Praxis oft nur schwer zu unterscheiden. In den meisten Fallen sind fur persistierende Beschwerden eine inkomplette Spaltung des Retinaculum flexorum oder eine Traktionsneuropathie verantwortlich, wahrend iatrogene Nervenlasionen selten sind. Echte Rezidive, die eine erneute Kompression des N. medianus durch das Zusammenwachsen des initial gespaltenen Lig. carpi transversum verursachen, sind sehr selten 3 . Eine genaue Anamnese in Verbindung mit einer grundlichen klinischen Untersuchung ist fur die Diagnosestellung unerlasslich. Eine erganzende bildgebende und neurografische Untersuchung kann hilfreich sein 4 5 . Haufig kann die Ursache allerdings trotz aufwendiger apparativer Diagnostik praoperativ nicht sicher bestimmt werden.