Pyrocarbon interposition implant after lunate resection in Kienböck's disease: A case series

In advanced stages of Kienböck's disease, the lunate is no longer conservable. One of the surgical options is to resect the lunate and replace it with a prosthesis. The procedure consisted in lunate resection and interposition of a free APSI® or Pi2® pyrocarbon implant through a dorsal approach. Follow-up was clinical and radiological on QuickDASH and PRWE scores. At a median follow-up of 3 years, 12 patients were reviewed, with a median age of 56 years. Flexion significantly decreased from 42° to 28° (p < 0.01). Extension and pronation-supination were conserved. Strength was 94% compared to the opposite side, with no significant difference from the preoperative measurement. Median QuickDASH and PRWE scores were 15.9 and 23.5 respectively and had significantly improved. One patient underwent scaphocapitate fusion because she was still in pain; the other patients were pain-free. No patients had to change jobs because of their wrist. Radiographically, there was no carpal collapse and carpal height was conserved. Radioscaphoid angle and ulnar translation were stable. There was 1 case of asymptomatic implant dislocation. Interposition of a pyrocarbon implant after lunate resection in advanced Kienböck's disease is a motion-conserving procedure that provides pain relief and functional recovery in the short and medium term. LEVEL OF EVIDENCE: IV.

Medium-term clinical and radiological results of surgically treated stage 3A Kienböck's disease

The purpose of this study was to compare the methods of distal radial shortening osteotomy (RSO), lateral closing distal radial wedge osteotomy (RWO), and scaphotrapeziotrapezoid (STT) fusion in the treatment of stage 3A Kienböck's disease (KD). The research was planned as a single-center and retrospective study for the period 2008-2018. Patients were allocated to three groups according to surgical method: group 1, patients with negative ulnar variance, undergoing RSO; group 2, patients with non-negative (neutral or positive) ulnar variance, undergoing RWO; and group 3, patients with non-negative ulnar variance, undergoing STT fusion. Radiological measurements were compared: pre- and postoperative Stahl index, radioscaphoid angle, and carpal height ratio. Clinical comparison used QuickDASH and modified Mayo wrist scores. Fifty-one patients, with a mean age of 34 ± 12 years (range; 16-69 years), were included. Mean follow-up was 4.47 ± 1.8 (range 2-9) years. No statistically significant difference was observed between the groups in terms of change in carpal height ratio or Stahl index (respectively; P = 0.08, P = 0.065). A significant difference was observed in change in radioscaphoid angle between patients undergoing STT fusion versus RWO (P < 0.05). There was no statistically significant difference in postoperative functional scores between groups, and similar postoperative functional scores were achieved with STT fusion and with RWO in the surgical treatment of stage 3A KD with positive or neutral ulnar variance. Good medium-term radiological and clinical results were obtained with RSO in patients with stage 3A KD with negative ulnar variance.

Improvement in lunate perfusion after radial closing-wedge osteotomy in patients with Kienböck's disease

Radial closing-wedge osteotomy is a widely accepted treatment for Kienböck's disease. However, despite favorable long-term clinical outcomes, its impact on lunate perfusion has not been documented. The purpose of this study was to determine whether radial closing wedge osteotomy improved lunate perfusion on gadolinium (Gd)-enhanced magnetic resonance imaging (MRI). We conducted a retrospective review of 12 patients with Kienböck's disease who received radial closing wedge osteotomy. Mean age at surgery was 25 years. Preoperative Gd-enhanced MRI was performed in 7 patients. After bone union, implants were removed and MRI was repeated. Two patients were classified as Lichtman stage IIIA, and 5 as stage IIIB. Percentage pre- to post-operative perfused lunate volume was compared on MRI. At last follow-up, mean QuickDASH score improved from 43.7 to 6.2. Pre- to post-operative lunate fragmentation, collapse and perfusion were compared qualitatively on MRI. On quantitative analysis, perfusion increased from 24% to 54% (p = 0.018) using our method of measuring percentage perfused lunate volume. The method showed satisfactory reproducibility. Investigation using Gd-enhanced MRI suggested that radial closing wedge osteotomy increases lunate perfusion.

Radial shortening osteotomy vs partial capitate shortening osteotomy in Kienböck's disease: Medium-term radiological and clinical results

This study aimed to compare medium-term results for partial capitate shortening (PCS) and radial shortening (RS) osteotomies on lunate bone revascularization and disease progression in patients with stage II or IIIA Kienböck's disease. Patients who underwent surgery for Kienböck's disease between March 2010 and July 2020 were retrospectively evaluated. Clinical evaluation included assessment of pain, joint range of motion, strength, DASH, visual analog scale (VAS) for pain, Modified Mayo Wrist Score (MMWS), satisfaction and time to return to work, with comparison as appropriate to the contralateral side. Preoperative and postoperative plain radiographs and magnetic resonance imaging (MRI) were used for radiological evaluation. Lichtman staging and signal changes in the lunate were evaluated using MRI. Group 1 (PCS) included 14 patients and Group 2 (RS) 14. Mean follow-up was 57.8 months (range 24-102) in Group 1 and 49.4 months (range 36-73) in Group 2. Clinical evaluation included pain on VAS, DASH score, MMWS, range of motion, and grip, palmar and key pinch strength. Regarding lunate bone vascularization, increased signal on final follow-up MRI was observed in 10 of the 14 patients in Group 1 and 7 of the 14 patients in Group 2. There was a positive correlation between revascularization and final follow-up MMWS (p = 0.006). The present study thus showed that functional scores were improved by revascularization in Kienböck's disease. Both osteotomies had clinically and radiologically satisfactory results. However, we believe that PCS osteotomy is preferable, as it leads to higher revascularization rates without increasing ulnolunate load.

Lunate biomechanics: application to Kienböck's disease and its treatment

Kienböck's disease was initially considered as lunate osteomalacia due to lesions of its nutrient arteries during carpal ligament tears. It has also been suggested following primary fractures, or because of repeated microtrauma. It is only in the past 20 or 30 years that it has appeared as aseptic necrosis. Based on Hultén's hypothesis that a negative radioulnar index was the cause of Kienböck's disease, equalization osteotomies (shortening of the radius or lengthening of the ulna) were developed. The observation of Kienböck's disease in subjects with a positive index and the risk of ulnar abutment after osteotomy led to the introduction of new osteotomies to get around these difficulties, still in the hope of treating the cause of Kienböck's disease. While it has been confirmed that a negative radioulnar index promotes lunate fracture, it clearly does not induce the pathology in the form of necrosis. In this scenario, perilunar osteotomies produce durable decompression, limiting the risk of lunate fracture in case of necrosis by removing the compressive constraints. After comparing the different osteotomies used to treat Kienböck's disease, it seems that the Camembert osteotomy for radius shortening, combined with selective shortening of the ulnar head as described by Sennwald, decompresses the lunate maximally, and protects it long enough for potential natural revascularization to occur.

Use of 4+5 extensor compartmental vascularized bone graft and K-wire fixation for treating stage II-IIIA Kienböck's disease

Vascularized bone grafts have shown favorable outcomes in Kienböck's disease, preventing the progression of lunate collapse and avascular necrosis. Here we describe our experience using a 4+5 extensor compartmental artery (ECA) vascularized bone graft combined with K-wire fixation. Between September 2010 and June 2013, 9 patients with Lichtman stage II-IIIA disease underwent arthroscopy prior to 4+5 ECA graft placement combined with temporary fixation (scaphocapitate and triquetrum-capitate joints). The average follow-up was 69 months (range, 51-92 months). Changes in pain, range of motion, grip strength, and pinch strength were analyzed. All patients had satisfactory recovery, especially pain relief and grip strength improvement (both P<0.01). Furthermore, magnetic resonance imaging follow-up was critical for monitoring lunate revascularization, especially in the early postoperative period.

Evaluation of a shape memory staple (Qual®) in radial shortening osteotomy in Kienböck's disease: A retrospective study of 30 cases

The QUAL^® (Memometal, Stryker) device is a shape memory staple used for bone fixation during distal radius shortening osteotomy in the context of Kienböck's disease. The present study is a retrospective, single-center and multisurgeon study of 30 patients with a mean follow-up of 8 years. Clinical criteria (range of motion (ROM), strength, pain and functional score) and radiographic data (ulnar variance, distal radius articular surface inclination, Lichtman stage, carpal height and bone healing) were evaluated pre- and post-operatively. We found satisfactory results with the mean grip strength of 22 kg/F before surgery and 24 kg/F after surgery. The mean ROM was 88° preoperatively and 82° postoperatively and the mean ulnar deviation was 23° preoperatively and 21° post-operatively. There was no change in radial deviation and pronation-supination after surgery. The average ulnar variance was 1 mm before surgery and 0.2 mm after surgery. The inclination of the distal radius articular surface on lateral and anteroposterior views and the mean carpal height were similar to the pre-operative ones. There was no delay in bone healing. The mean pain score was 2 at rest on a visual analogue scale after surgery. Seven patients experienced an increase in their Lichtman stage at the follow-up, and two patients were waiting for conversion to a non-conservative surgical treatment. Seven staples were removed postoperatively. Seventy-eight percent of patients returned to work after 3 months on average. Seventy-five percent of patients were at least satisfied with the outcome of their surgery. The QUAL^® staple is a reliable option for fixation during shortening osteotomy of the radius in Kienböck's disease.

Idiopathic bilateral lunate and triquetrum avascular necrosis: A case report

We report on the case of bilateral avascular osteonecrosis (AVN) of the lunate and triquetrum in a 45-year-old woman without any relevant medical history for which the cause could not be established. She was treated conservatively with splinting and analgesics. The patient was able to pursue her work and hobbies with subnormal range of motion at 1-year follow-up. AVN of the triquetrum is very rare, as it is a richly vascularized bone. The presence of AVN in multiple carpal bones has only been described in patients receiving high doses of corticosteroids. To our knowledge, there are no other cases of idiopathic AVN of multiple carpal bones in the literature.