Scaphoid Nonunion Advanced Collapse: Denervation

Fig. 22.1

Fig. 22.2

Diagnosis

The conducted clinical and radiographical examinations (Figs. 22.1 and 22.2) were consistent with Stage III scaphoid nonunion advanced collapse (SNAC), mostly ascribable to a scaphoid fracture related to the previous sports accident .

Management Options and Management Chosen

Therapeutic decision-making in patients with SNAC wrist is based on a careful assessment of both the case history (taking account of patients age, profession, and dominant hand), as well as on the bone and cartilage status of the wrist, ascertained by radiographs and if indicated, by arthroscopy of the wrist, respectively. This allows a meaningful restriction of different conservative and surgical treatment approaches, such as nonunion repair, partial fusions of the carpus (e.g., four-corner fusion), proximal row carpectomy , wrist arthrodesis, radial styloidectomy , and wrist denervation [1].

In this specific case, we discussed in detail the clinical and radiological findings with the patient. Because of a radiological evident OA in the radiocarpal joint, no strategy of scaphoid repair was proposed. Proximal row carpectomy was contraindicated because of radiographic evidence of OA of the head of the capitate and in the midcarpal compartment. Since signs of OA between the lunate and the lunate fossa in the radiographs were scarce, we proposed to evaluate the intra-articular situation of the cartilage in the different joints by wrist arthroscopy. In case of intact cartilage layers between the lunate and lunate fossa, a four-corner fusion is alternatively proposed to wrist denervation as a salvage procedure. In case of cartilage damage in the lunate fossa, wrist denervation is more often chosen by patients before going to wrist arthrodesis .

Surgical Technique

Arthroscopy

The arthroscopy was performed with an upper-arm tourniquet. The hand was placed in stiff finger traps. 5 kg vertical traction was applied through a traction tower. First, the radiocarpal compartment was inspected through the 6R portal. Synovitis pervaded the radiocarpal compartment. The cartilage surface of the scaphoid and lunate fossa revealed grade IV chondromalacia, and the adjacent proximal articular surface of the lunate revealed grade II-III chondromalacia (Fig. 22.3) .

Fig. 22.3

Thereafter, the midcarpal compartment was inspected through the MCR portal which revealed grade II-III chondromalacia in the whole compartment, especially of the proximal pole of the capitate and the tip of the hamate (Fig. 22.4). It revealed OA with complete loss of cartilage due to the scaphoid nonunion.

Fig. 22.4

Wrist Denervation in the Same Setting

Based on the arthroscopic findings and the assessed radiocarpal and midcarpal damages, we opted for complete wrist denervation as proposed by Wilhelm [2]. After removing the traction, the hand was placed on hand table for wrist denervation . A curved incision was performed on the dorsal distal forearm just proximal to the DRUJ (Figs. 22.5 and 22.6). Thereafter, the cutaneous and subcutaneous layers are separated from the fascia layer. Perforating nerve branches were coagulated and transected . By doing so in proximal, distal, radial, and ulnar directions, the totality of the dorsal fascia was exposed like in a degloving injury. The fascia was incised in the area next to the muscle belly of the extensor pollicis longus. The muscle belly is retracted radially and the tissues lying on the interosseous membrane are exposed. A 2-cm segment of the posterior interosseous nerve (PIN) was coagulated and resected (Fig. 22.7). Next, a dorsoradial incision corresponding to the level of the trapeziometacarpal joint was made. The perforating branches originating from the superficial radial nerve and innervating the radial wrist capsule were coagulated and transected, protecting the cutaneous branches (Fig. 22.8). Another longitudinal incision was made just above the radial artery. The surrounding tissue was prepared in radiodorsal direction in order to create a communication with the previously prepared area on the dorsal side and to again interrupt the perforating branches of the superficial radial nerve. The radial artery was exposed using microsurgical technique and the periarterial tissue was coagulated and also resected (Fig. 22.9). Subsequently, the final volar incision was made. The palmar fascia was opened and the pronator quadratus muscle was lifted at the distal edge. Thereafter, the periosteum on the palmar aspect of the distal radius was removed under extensive coagulation. Branches of the anterior interosseous nerve (AIN) were intensively coagulated volar to the DRUJ. Following wound closure, postoperative immobilization was not necessary .