Anatomy of the anterior interosseous innervation of the pronator quadratus: evaluation of structures at risk in the single dorsal incision wrist denervation technique

PURPOSE: Patients with chronic wrist pain often are treated with wrist denervation, which typically involves transecting both the anterior interosseous nerve (AIN) and the posterior interosseous nerve. A single dorsal incision approach is an improvement over the more traditional multiple-incision technique. The purpose of our study was to describe the branches of the AIN to the pronator quadratus and evaluate the risk of denervation with the single dorsal incision technique. METHODS: Twelve fresh-frozen cadaver forearms were dissected. The branches of the AIN to the pronator quadratus were identified and the individual branch points were measured from the articular edge of the distal radius. Wrist denervation was then performed on each specimen through the single dorsal incision (as suggested by Berger). RESULTS: There were an average of 3 branches from the AIN to the pronator quadratus. All forearms had at least 1 branch to the pronator quadratus more proximal to the distal end of the dorsal skin incision; however, in only 2 of the forearms was the most proximal branch more than 2 cm proximal to the distal end of the dorsal skin incision. CONCLUSIONS: Wrist denervation through the recommended single dorsal incision poses a serious risk for completely denervating the pronator quadratus. Therefore the resection of the AIN must be performed close to the distal margin of the pronator quadratus.     

The surgical anatomy of thoracic facet denervation

Summary Thoracic percutaneous facet denervation has been employed for the treatment of thoracic zygapophysial joint pain. But the surgical anatomy of this procedure has been assumed to be the same as for lumbar medial branch neurotomy. To establish the anatomical basis for thoracic medial branch neurotomy, an anatomical study was undertaken. Using an X40 dissecting microscope, a total of 84 medial branches from 7 sides of 4 embalmed human adult cadavers were studied.The medial branches of the thoracic dorsal rami were found to assume a reasonably constant course. Upon leaving the intertransverse space, they typically crossed the superolateral corners of the transverse processes and then passed medially and inferiorly across the posterior surfaces of the transverse processes before ramifying into the multifidus muscles. Exceptions to this pattern occurred at mid-thoracic levels (T5–T8). Although the curved course remained essentially the same, the inflection occurred at a point superior to the superolateral corner of the transverse process.At no time during the dissection were nerves encountered crossing the junctions between the superior articular processes and transverse processes which have been the target points advocated for thoracic facet denervation. Rather, the results of this study indicate that the superolateral corners of the transverse processes are more accurate target points.     

Wrist denervation and the anterior interosseous nerve: anatomic considerations

PURPOSE: Wrist denervation via resection of the distal anterior interosseous nerve (AIN) and the posterior interosseous nerve (PIN) is an effective treatment for chronic wrist pain. When performing this procedure through a dorsal approach we have been impressed by anatomic variations of the AIN. This has raised concerns about potential denervation of the pronator quadratus (PQ). The purpose of this study was to elucidate the anatomy of the AIN and PIN as encountered through a dorsal distal forearm incision. METHODS: Ten fresh-frozen cadavers were dissected. Before dissection radiographs were obtained to ensure accurate localization of the proximal ulnar head with a radiopaque marker. A dorsal approach to the distal forearm was made to identify the anatomy of the PIN and AIN. The location and diameter of all AIN branches were noted by using an operating stereoscopic microscope at x 25 magnification and a precision caliper. The PIN anatomy and size also were noted. RESULTS: The anatomy of the AIN was variable. The average AIN diameter proximal to the PQ was 1.5 mm. The average number of AIN motor branches was 4.2. The largest PQ motor branch was the first motor branch and was located at an average distance of 37.9 mm from the proximal ulnar head. The last motor branch was found an average of 23.9 mm from the proximal ulnar head. In 9 of 10 specimens the sensory branch tunneled radially through the distal PQ and innervated the periosteum of the volar distal radius. In 4 of 10 specimens a separate branch to the distal radioulnar joint was present. We found an average PIN diameter of 0.87 mm. CONCLUSIONS: Resection of the AIN at a point 4 cm proximal to the proximal point of the ulnar head would denervate completely the PQ in our cadaver population. Division of the AIN 2 cm proximal to the ulnar head would spare most of the PQ motor branches.     

腕关节色素绒毛结节性滑膜炎误诊1例

1　临床资料患者 ,女 ,5 0岁。 1995年无意中发现右腕尺背侧有一包块 ,蚕豆大小 ,无疼痛 ,不影响腕关节活动 ,当时未就诊。此后肿块缓慢生长 ,1年后增大约1倍 ,在当地乡镇医院诊断为腱鞘囊肿 ,未治疗。 2 0 0 0年 8月 2 0日 ,因肿块显著增大 ,且右腕胀痛来院就诊。检查 :右腕尺背侧有一 5ｃｍ× 3ｃｍ× 1ｃｍ大小肿块 ,外形不规则 ,局部肤色正常 ,质软 ,能活动 ,尺骨茎突处压痛 ,腕关节活动无明显异常。Ｘ线片检查未见明显异常 ,超声检查示右腕关节尺侧有一实性包块 ,边界清晰 ,形态不规则 ,内回声不均匀。诊断为脂肪瘤。2天后行肿块切除术…     

The instability of wrist joint and total wrist replacement

Total wrist arthroplasty are not used as widely as total knee and hip replacement. The functional hands are requiring surgeons to design a durable and functional satisfying prosthesis. This article will list the main reasons that cause the failure of the prosthesis. Some remarkable and representative prostheses are listed to show the devolvement of total wrist prosthesis and their individual special innovations to fix the problems. And the second part we will discuss the part that biomechanical elements act in the total wrist replacement (TWA). Summarize and find out what the real problem is and how we can find a way to fix it.     

Partial arthrodesis of the wrist: An investigation in cadavers

Partial arthrodesis of the wrist was performed on six cadavers in order to study the residual excursion of the wrist. Arthrodesis between the radius and scaphoid left 40 per cent extension/flexion and 61 per cent radial/ulnar deviation. Arthrodesis between the radius, scaphoid and lunate left 36 per cent extension/flexion and 59 per cent radial/ulnar deviation. Arthrodesis between the capitate, scaphoid and lunate left 59 per cent extension/flexion and 91 per cent radial/ulnar deviation.     

Biaxial total wrist arthropla

Arthrodesis is a reliable and predictable method of treating patients with symptomatic radiocarpal joint destructionand should be recommended in most cases. However, some patients are not able to compensate for the lack of wrist mobility associated with wrist fusion because of multiple joint arthroses as are commonly seen in patients with rheumatoid arthritis. For these patients, total wrist arthroplasty is best described as a higher risk and higher reward procedure. A recent review of 64 cases of total wrist arthroplasty found an 83% implant survival rate at a mean follow-up period of 6.5 years. Clinical results showed excellent patient satisfaction and very good pain relief and range of motion. Of the patients who failed arthroplasty and were eligible for revision total wrist arthroplasty, 80% elected revision arthroplasty over recommended arthrodesis. This report reviews patient selection, technique, postoperative management, management of complications, and expected outcome of biaxial total wrist arthroplasty.     

Effect of wrist position on distal radioulnar joint stability: A biomechanical study

We investigated distal radioulnar joint (DRUJ) stability in different wrist positions and examined the relative contribution of each ligamentous component of the triangular fibrocartilage complex (TFCC) to DRUJ stability. We used nine fresh‐frozen cadavers. The humerus and ulna were fixed at 90° elbow flexion. The radiocarpal unit was translated relative to the ulna in dorsopalmar directions with the wrist in five positions. Displacement of the unit was measured by an electromagnetic tracking device. Magnitudes of displacement were compared between different wrist positions in various sectioning stages: ulnocarpal ligament (UCL) sectioning, radioulnar ligaments (RUL) sectioning, and extensor carpi ulnaris (ECU) floor sectioning. Wrist position and sectioning stage significantly influenced the displacement. In intact wrists, the displacement in wrist extension was significantly lower than that in neutral. However, after UCL sectioning, there were no longer any significant differences. After RUL sectioning, the displacement in radial deviation was significantly lower than that in neutral. Following ECU floor sectioning, there were no longer any significant differences. Thus, in intact wrists, DRUJ stability in wrist extension is likely due to tightening of the UCL. After complete RUL sectioning, DRUJ is stabilized in radial deviation due to tightening of the ECU floor. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1247–1251, 2014.     

Denervation of the Wrist Joint - An Alternative in Conditions of Chronic Pain

Nine patients with chronic pain in the wrist secondary to lunatomalacia and non-union of the scaphoid bone were treated by denervation of the wrist joint. This operation was first presented by Wilhelm in 1966. We have been using a modified technique. the purpose of the operation is to achieve relief of pain by selective neurotomy without impairment of hand function and with preservation of wrist mobility. Eight patients were considerably improved; one was not helped at all. No appreciable progression of the pathological changes have occurred radiographically during the period of follow-up. We find our results encouraging and the method worth trying.     

Differential adrenergic response to extrinsic denervation in canine longitudinal jejunal and ileal smooth muscle

Early postoperative complications after small bowel transplantation (SBT) are likely mediated, at least in part, by dysmotility caused by the obligate disruption of extrinsic and enteric nerves in the graft. Adrenergic hypersensitivity of gut smooth muscle has been observed in some (but not all) segments of intestine in various experimental models of SBT, highlighting regional and species variability in response to denervation. Little is known about changes in canine longitudinal muscle after extrinsic denervation. Six dogs each underwent either complete extrinsic denervation of the jejunoileum or a control operation (transection and reanastomosis of the proximal jejunum and distal ileum). In vitro contractile response of longitudinal muscle strips to norepinephrine was evaluated at the time of the operation, and 2 weeks and 8 weeks later. After extrinsic denervation, the jejunal response to norepinephrine was preserved at all time points; however, the ileum displayed a decreased sensitivity to norepinephrine, an effect unmasked after intramural neural blockade with tetrodotoxin. These data support a potential for neurally mediated dysmotility after SBT and reinforce the differences in responses to extrinsic denervation between species, as well as differences within different regions and between anatomic segments of small intestine in the same species. Presented in part at the Ross Residents and Fellows Research Conference and the Forty-Second Annual Meeting of The Society for Surgery of the Alimentary Tract, Atlanta, Georgia, May 20–23, 2001 (poster presentation); and published as an abstract in Gastroenterology 120:A351, 2001. Supported by grants from the National Institutes of Health (NIH DK39337 and NIH DK07198) and the Mayo Foundation.