Metaphyseal Core Decompression of the Distal Radius for Early Lunate Necrosis

Background: Metaphyseal core decompression of the distal radius (MCD) is clinically effective in early lunate necrosis without changing individual wrist mechanics. Its concept is based on the induction of physiologic mechanisms known as physiologic fracture healing response. However, this biological concept does not yet have its place in the historically developed mechanical concepts about Kienböck’s disease and requires more detailed clarifications to understand when a change of individual wrist mechanics might be unnecessary. Methods: Thirteen consecutive cases, Lichtman stage I (n = 1) or II (n = 12), confirmed by conventional MRI, were treated by MCD. Time off work, changes in magnetic resonance imaging of the lunate, as well as clinical outcome using modified Mayo wrist score were evaluated at final follow-up. Results: Return to work was at six (1–10) weeks after surgery. MRI controls at short-term generally demonstrated stop of progression and signs of bone healing. Independently from ulna variance complete signal normalization was observed in six and a distinct, yet incomplete decrease of lunate bone marrow edema and zones of fat necrosis was confirmed in further six cases after a mean of 21 (13–51) weeks. One patient had radiographic controls only, stating normal healing at 56 months. After a mean follow-up of 37 (12–70) months the clinical outcomes were excellent in eleven and good in two cases (mean 95% in modified Mayo wrist score). Conclusions: In stage I and II lunate necrosis MCD stops disease progression, it improves clinical symptoms and induces normalization of lunate bone signal alterations in MRI. Findings suggest that stage I and II lunate necrosis can be effectively treated without alterations of individual wrist mechanics. Future studies are necessary to readjust common concepts regarding Kienböck’s disease, especially focusing on conservative therapy.

ARTHROSCOPIC ASSESSMENT OF THE WRIST WITH KIENBÖCK’S DISEASE

ABSTRACT Objective: Treatment of Kienböck's disease is challenging and the variability of results, despite the surgical technique, shows that there must be other aspects that can influence outcomes. The objective of this study is determine, through arthroscopic approach, the pattern of impairment of the carpal bones in Lichtman stage III patients. Method: Wrist arthroscopy was performed in patients with symptoms and evidence of lunate necrosis on x-rays, with signs of 3A and 3B stages. The Outerbridge classification was used to grade the articular status of the carpal bones. Results: Fifteen patients with stage 3 disease were assessed, five of whom were staged as type 3A and ten as 3B using the Lichtman stages. According to the Outerbridge classification, the lunate sulcus was the most affected with means of 2.8 at 3A and 2.9 at 3B. Other areas were significantly less affected with means of 1.1 and 1.3, respectively. Conclusion: Arthroscopic assessment of the wrist could aid in surgical decision making, offering more details on cartilage status in stage 3 Kienböck's disease. Level of Evidence III, Study of nonconsecutive patients, without consistently applied reference “gold” standard.

Scapholunate Ligament Repair Using the Mitek™ Bone Anchor

A retrospective study was done to assess the outcome after repair of completely ruptured scapholunate interosseous ligaments using the Mitek™ Mini G2 bone anchor. From 1994 to 1996. 12 patients underwent scapholunate ligament repair using the bone anchor. A follow-up assessment was done at a mean of 19 months postoperatively and revealed excellent or good results in eight patients, satisfactory in two, and poor in two patients, one of whom had developed lunate necrosis. One patient with an excellent functional result demonstrated recurrent dissociation of the scapholunate gap radiographically. The technique described proved to be simpler than conventional procedures in our hands, and yields similar functional results.

A NEW CLASSIFICATION OF LUNATE NECROSIS

The classifications of lunate necrosis used by Decoulxet al. (1957)3 and Lichtmanet al. (1977)7 and Lichtman and Degnan (1993),6 respectively, do not refer to early changes in MRI nor to changes to the carpal architecture, but do attribute the onset of the disease to the presence of a fracture. A recent publication of Lichtman and Ross (1994)8 did not solve the problem of a precise description of the disease. This necessitates a new, reliable classification based on the true natural course of the disease. In a prospective study of 49 patients and in a retrospective analysis of 125 lunate necrosis, the findings obtained prove the regular natural course of the disease. It starts with normal x-ray appearance but the intensity of the signal in T1-weighted MRI is decreased; a fracture line is part of the latter course and not the beginning. It precedes the collapse of the lunate, followed by the collapse of the carpus and the arthritis of the wrist.