ABSTRACT

CORRESPONDING AUTHOR:
Dr. B. Suresh Gandhi,
No. 5, Cauvery Cross Street,
Devi Nagar, RCC Post, Annanoor,
Chennai – 600109, Tamilnadu, India.
E-mail: bsg.ortho@gmail.com

ABSTRACT: We treated a patient with advanced stage kienbocks disease by scaphocapitate fusion and posterior interosseous nerve neurectomy. The patient is a young adult 30 years of age working as manual laborer. At 30 months follow up, wrist range of movements improved, excellent pain relief and greater patient satisfaction. We believe the limited carpal fusion is a good option in advanced kienbocks disease in select group of patients and posterior interosseous nerve neurectomy as a salvage procedure provides excellent pain relief with high satisfaction rates.

KEYWORDS: Kienbocks disease, limited carpal fusion, posterior interosseous nerve neurectomy.

INTRODUCTION: Kienbocks disease is osteonecrosis of lunate bone, it progresses slowly to various stages of disease, eventually lunate bone collapses, altering surrounding carpal bone architecture. The etiology of osteonecrosis of lunate bone is still a controversy. Various theories are reported to explain the etiology like variation in blood supply to the lunate bone, repetitive trauma and abnormal stress in radiocarpal joint due to ulnar variance.^1,2 Numerous surgical procedure are described for advanced lunate osteonecrosis with varied result. In advanced stages of kienbocks disease salvage surgeries like lunate replacement, lunate excision, proximal row carpectomy, limited carpal fusion, and wrist fusion has been described without any strong evidence supporting any one procedure.

CASE REPORT: Young adult aged 25 years reported to our hospital with complaints of left wrist pain and difficulty in doing work. The symptoms are progressively worsening for past one year. He had relief of symptoms with medication and rest. On examination restriction of wrist range of motion and local tenderness on lunate bone. Plain radiograph of the left wrist revealed sclerosis, fragmentation and collapse of lunate bone with normal ulnar variance and normal radiolunate articular surface. Magnetic resonance imaging of the left wrist, lunate appeared hyperintense in T1 and heterointense in T2 with collapse and minimal degenerative changes. The imaging was compatible with type 3 b kienbocks disease. Scaphocapitate fusion to offload the stress on lunate bone, preserving the wrist range of motion and Posterior interosseous nerve neurectomy for pain relief was planned.

PROCEDURE: Through 3 cm skin incision 1 cm proximal to the distal radioulnar joint, between 3^rd and 4^th extensor compartment, posterior interosseous nerve identified over interosseous membrane, isolated and cut. Lunate bone exposed through the middorsal incision. Graft area prepared for fusing capitate and scaphoid done. Bone graft harvested from the distal radius and impacted between scaphoid and capitate and stabilized with K-wire. Below elbow cast maintained for 8 weeks till signs of scaphocapitate fusion. On postoperative day one patient had relief of preoperative pain.

At six months follow up – range of movements of wrist and grip strength improved. Height of lunate was maintained with signs of fusion of scaphoid and capitate in plain radiograph of wrist.

At final 30months follow up, wrist range of movements and grip strength improved. He was able to do heavy job, DASH score was 31.

DISCUSSION: In advanced kienbocks disease the progressive collapse of the lunate bone alters biomechanics of the surrounding carpal bones producing proximal capitate migration and decreased carpal height. The treatment should reduce the load across the radiolunate joint and prevent further carpal collapse. The surgical procedures like proximal row corpectomy, scapho- trapeziotrapezoid fusion, scaphocapitate fusion, radial osteotomy, interposition arthroplasty are done to accomplish these goals.

Pain relief, increase in range of motion of wrist and increase in grip strength have been reported following proximal row corpectomy. The proximal row corpectomy should be done with caution in advanced kienbocks disease and patient age below 35 years.^{3, 4}

Limited carpal arthrodesis like STT and SC has been reported to get good results by stabilizing the midcarpal joint and arresting the proximal migration of carpal bones.^{5, 6} The advantage of scaphoid capitate fusion over scaphotrapeziotrapezoidal fusion are large bony area for fusion and only one articulation to fuse.⁷

In our case report we have done scaphocapitate arthrodesis to stabiles the midcarpal joint, preventing proximal migration of carpal bone and offload the lunate bone. Scaphocapitate fusion was achieved in 3 months post operation. At 30 months follow up post-operation carpal height is maintained, no proximal migration of the capitate bone and no obvious signs of worsening of radiolunate arthritis.

Wrist denervation procedures are done as a salvage procedure for advanced stage kienbocks disease. In our case study posterior interosseous nerve neurectomy was done to reduce the arthrosis pain. The patent had significant pain relief and high satisfaction rate.

A. D. Tambe et al reported in his study comparing wrist fusion with limited wrist fusion in advanced kienbocks disease, visual analogue pain scores, patient satisfaction scores and SF12 were better in wrist fusion group. Limited fusion group did better in DASH score, wrist range of motion and grip strength.⁸

In limited carpal fusion there is a possibility of degenerative changes in radiocarpal and midcarpal joints and potential for deterioration of results over time, due to change in wrist biomechanics.⁹

CONCLUSION: Scaphocapitate fusion in select group of patients below 35 years of age is an good option as it preserves wrist range of motion, good grip strength; probably addition of posterior interosseous neurectomy has been responsible for excellent pain relief and high satisfaction rate. Further follow up will let us know whether there is any progression of arthrosis and need to do wrist fusion.

REFERENCES:

1. Geiberman R H, Bauman TD, Menon J et al. The vascularity of the lunate bone and kienbock’s disease. J Hand Surg Am.1980; 5:272-278.
2. Bonzar M, Firrell JC, Hainer M et al. Kienbock disease and negative ulnar variance. J Bone Joint Surg Am.1998; 80: 1154-1157.
3. Croog AS, Stern PJ. Proximal row carpectomy for advanced Kienbo¨ck’s disease: average 10-yearfollow-up. J Hand Surg Am.2008; 33:1122–30.
4. DiDonna ML, Kiefhaber TR, Stern PJ. Proximal row carpectomy: study with a minimum of ten years of follow-up. J Bone Joint Surg Am.2004; 86:2359–65.
5. Linscheid RL. Kienbock’s disease. Instr Course Lect.1992; 41: 45–53.
6. Watson HK, Monacelli DM, Milford RS, et al. Treatment of Kienbo¨ck’s disease with scaphotrazio-trapezoid arthrodesis. J Hand Surg Am.1996; 21:9–15.
7. Pisano SM, Peimer CA, Wheeler DR. Scaphocapitate intercarpal arthrodesis. J Hand Surg Am. 1991; 16: 328–33.
8. A. D. Tambe . I. A. Trail . J. K. Stanley. Wrist fusion versus limited carpal fusion in advanced Kienbock’s disease. International Orthopaedics.2005;29: 355–358.
9. Garcia-Elias M, Cooney WP, An KN et al. Wrist kinematics after limited intercarpal arthrodesis. J Hand Surg Am.1989;14 :791–799.

Fig. 1: Pre-Operative X-Ray- Sclerosis  and fragmentation of lunate bone

Fig. 2: Pre-op MRI-Lunate is hyperintense  in T1,  heterointense  in T2 with collapse

Fig. 3:Pre-op Range of motion

Figure 4: Intra-op picture; a] posterior interrosseous  nerve isolated. b] lunate bone exposed

Figure 5: Immediate post op X-Ray

Figure 6: Post –op Xay after 30 months; Maintenance of carpal height,  No arthritic changes in radiolunate joint

Figure 7: Post –op 3 months Range of motion