[Abstract] Objective To evaluate the effect of four-joint fusion of the skull, lunar, triangular and hook bones in the treatment of traumatic wrist arthritis. Methods From July 1997 to December 2002, 20 cases of traumatic wrist arthritis were treated with partial fusion of the wrist joint, and follow-up was obtained 15 months after surgery. Follow-up examinations included the degree of postoperative wrist pain, wrist mobility, grip strength, and X-ray examination of the affected side. The degree of pain was evaluated by visual analog scoring method. Overall wrist function was evaluated using the Krimmer wrist score. The Krimmer wrist score was 67. X-ray examination showed that the cephalo-lunar triangle and hook bone were fused. Conclusion Partial fusion of the wrist joint to preserve partial function of the wrist joint is a better treatment for wrist arthritis.
【Key words】Wrist; partial wrist fusion; clinical efficacy
In the past, total wrist fusion was used for degenerative wrist arthritis, which resulted in loss of wrist function after surgery and affected patients’ quality of life. In our department, fusion of the cephalic, lunar, triangular and hook bones of the wrist was used to treat degenerative radial carpal arthritis caused by non-union of the navicular fracture and separation of the navicular and lunar bones, which preserved some wrist functions.
Clinical data
From July 1997 to December 2002, 20 cases of degenerative carpal arthritis were treated with fusion of the lunar, triangular, cephalic, and hook bones in our department. There were 15 male cases and 5 female cases, with an average age of 40 years (36-60 years). There were 12 cases in the left hand and 8 cases in the right hand. The follow-up time was 15 months (10-73). 15 of the 20 patients had radial carpal arthritis due to non-healing navicular fracture and 5 had radial carpal arthritis due to injury to the navicular ligament. x-ray radial carpal arthritis was divided into three stages: stage I: carpal arthritis was confined between the navicular bone and the radial tuberosity, stage II: carpal arthritis was between the radius and the navicular bone, and stage III: arthritis spread to the midcarpal joint. In our group, there were 7 cases of stage II and 13 cases of stage III wrist arthritis in 20 cases. 12 patients had preoperative CT examination of the wrist joint to assist in the typing of wrist arthritis.
Surgical method
After brachial plexus or general anesthesia was in effect and a balloon tourniquet was applied, an s-shaped incision was made on the dorsal surface of the wrist, layer by layer, to reveal the extensor tendon support band. The third extensor tendon sheath is incised sharply, and the fourth extensor tendon sheath is free along the surface of the wrist capsule through the third extensor tendon sheath. The thumb extensor tendon is pulled to the radial side, and the common extensor tendon is pulled to the ulnar side, and the base of the fourth extensor tendon sheath is searched for the interosseous dorsal nerve, and the 2M-long nerve segment is excised.
The dorsal carpal capsule was incised in a T-row, and the skull, lunar bone, triangular bone and hook bone were localized by intraoperative fluoroscopy. The wrist joint was extremely palmarly flexed, and the extent of arthritis in the radial carpal joint and midcarpal joint was observed, and the stage of carpal arthritis had been determined. The ligaments on the surface of the navicular bone are sharply stripped and the navicular bone is completely removed. Biting forceps were used to bite away the osteochondral bone adjacent to the four carpal bones of the lunar, triangular, and cephalic bones as well as the hook bone, filling in the cancellous bone of the ilium. The lunar bone was repositioned by drilling a 1.5 mm diameter restorative kerf pin from the dorsal side of the lunar bone to the palmar side, and two 1.0 L diameter kerf pins were drilled parallel to the lunar bone from the cranial bone to the lunar bone, then a third kerf pin was drilled from the cranial bone to the triangular bone, and finally a fourth kerf pin was drilled from the hook bone to the triangular bone. The wrist joint was fluoroscopically observed to see if the navicular bone was completely resected, if the lunate bone was repositioned and the position of the Creutzfeldt-Jakob needle, and the wrist joint was passively moved to see if the lunate bone obstructed the dorsiflexion of the wrist joint. After fluoroscopy, the repositioned Kirschner needle inserted into the lunate bone was removed, and the remaining Kirschner needle was cut and bent caudally. 5/0 absorbable sutures were used to close the wrist capsule and the third extensor tendon sheath. The skin was sutured.
The forearm plaster rest was externally fixed in dorsal extension of the wrist joint at 15°. The cast was removed 6-8 weeks after surgery and functional wrist exercises were performed. The internal fixation pin was removed at 12 weeks after the bone healing was confirmed by radiographs.
Follow-up method
The clinical examination included surgical complications, wrist scars, and hand sensation. Postoperative use of the affected hand was obtained by questioning the patient and was classified into four levels: normal hand function; only slightly impaired hand function; significantly limited hand function; and extremely limited hand function.
The objective functional evaluation indexes of the hand included wrist mobility, grip strength of the hand, and the degree of wrist pain at rest and after exertion, and wrist function was scored using the Krimmer scale. Bilateral wrist mobility included wrist flexion and extension and ulnar radial deviation, and wrist mobility was measured with a protractor. Bilateral grip strength was measured with a jamar grip strength device, and the average was taken three times for each side.
The degree of wrist pain was assessed by visual analogue scaleswith a pain value of 0 indicating no pain and a pain value of 10 indicating intolerable severe pain.
X-ray examinations: frontal and lateral X-rays were performed for each affected wrist joint at follow-up.
Results
There was no wound infection in any of the postoperative cases, the hand felt normal, and there were two cases of scar growth on the back of the wrist. The use of the affected hand was normal in 2 cases, only slightly impaired in 9 cases, significantly limited in 7 cases, and extremely limited in 2 cases.
Wrist pain values were 5.3±1.7 after weight-bearing and 2.1±1.0 at rest; preoperative wrist weight-bearing was 8.2±2.4 and resting was 4.7±1.8.
The dorsal extension and palmar flexion mobility of the wrist was 64º±15º and the contralateral mobility was 126º±25º; the mean ulnar radial deviation was 30º±8º and the healthy side was 57º±15.
The grip strength was 24±6K on the affected side and 40±11K on the healthy side.
The overall efficacy according to the Krimmer scale was excellent in 2 cases, good in 10 cases, satisfactory in 5 cases and poor in 3 cases, with a mean value of 67.
The x-ray examination showed that the lunar bone was not completely repositioned in two cases, and the lunar bone was still palmarly flexed, which affected the dorsal and extension activities of the wrist joint, and in two cases the Krimmer pin was too long, which did not affect the wrist joint activities after removal.
Discussion
The previous treatment for degenerative wrist arthritis used fusion of the entire wrist joint, and all wrist joint function was lost after fusion of the wrist joint. In the past decade, in-depth studies have been conducted on wrist arthritis lesions caused by non-union of the navicular fracture and separation of the navicular and lunar bones, and it was found that wrist arthritis mostly occurs between the radial navicular bone, and the lunar bone does not form arthritis with the radial bone for a long time, so the wrist joint can still maintain partial function after partial fusion of the wrist joint.
Because of the complex structure of the wrist joint, it is sometimes difficult to accurately determine the degree and extent of arthritis by simple x-ray examination. Currently, foreign countries use wrist arthroscopy to determine the stage of wrist arthritis. In addition, the dorsal carpal ligament can be opened during surgery to determine the extent of wrist arthritis under direct vision.
Carpal arthritis spread to the cephalic bone (stage III), the articular surface of the cephalic bone has been damaged, at this time, proximal row of carpal bone resection cannot be used, which is an absolute indication for carpal quadruple arthroplasty fusion. There is still a debate on whether to use proximal carpal osteotomy or partial fusion of the wrist joint for stage II wrist arthritis. Some scholars recommend direct proximal carpal osteotomy, because after proximal carpal osteotomy, the wrist joint can be moved early and the function can be restored earlier and better. However, some scholars suggest partial fusion of the wrist joint, which provides significantly stronger wrist strength than proximal carpal osteotomy.
The position of the lunate bone is very important during partial fusion of the wrist joint, and the incomplete repositioning of the lunate bone affects the dorsiflexion of the wrist joint. The small shape of the lunate bone makes it difficult to accurately reposition the lunate intraoperatively. We inserted a 1.5L diameter Kirschner pin into the lunate, and the lunate can be repositioned by moving the pin, and the lunate should be in a mildly hyperextended position. In two patients in this group, the lunate bone failed to be completely reset and was found to affect the dorsiflexion of the wrist joint during the examination.
We also resected the dorsal interosseous palmar and interosseous dorsal nerves at the same time as the partial fusion of the wrist, and clinical studies have shown that resection of these two nerves can significantly reduce wrist pain. In our study, we showed that after proximal carpal osteotomy with interosseous palmar dorsal nerve resection, wrist pain was reduced, which was related to the elimination of the cause of carpal arthritis and nerve resection after surgery.
In this clinical study, we found that after partial fusion of the wrist joint, wrist mobility remained up to 60% of normal, wrist strength reached 50%, pain was significantly reduced, and some wrist function was preserved.