ObjectiveTo provide anatomical basis for vascularized pisiform transfer in the treatment of advanced avascular necrosis of the lunate (Kienböck’s disease) by studying its morphology and blood supply pattern based on digital technique.MethodsTwelve adult fresh wrist joint specimens were selected and treated with gelatin-lead oxide solution from ulnar or radial artery. Then the three-dimensional (3D) images of the pisiform and lunate were reconstructed by micro-CT scanning and Mimics software. The morphologies of pisiform and lunate were observed and the longitudinal diameter, transverse diameter, and thickness of pisiform and lunate were measured. The main blood supply sources of pisiform were observed. The number, diameter, and distribution of nutrient foramina at proximal, distal, radial, and ulnar sides of pisiform were recorded. The anatomic parameters of the pedicles (branch of trunk of ulnar artery, carpal epithelial branch, descending branch of carpal epithelial branch, recurrent branch of deep palmar branch) were measured, including the outer diameter of pedicle initiation, distance of pedicle from pisiform, and distance of pedicle from lunate. ResultsThere were significant differences in the longitudinal and transverse diameters between pisiform and lunate (t=6.653, P=0.000; t=6.265, P=0.000), but there was no significant difference in thickness (t= 1.269, P=0.109). The distal, proximal, radial, and ulnar sides of pisiform had nutrient vessels. The nutrient foramina at proximal side were significantly more than that at distal side (P<0.05), but there was no significant difference in the diameter of nutrient foramina between different sides (P>0.05). The outer diameter of pedicle initiation of the recurrent branch of deep palmar branch was significantly smaller than the carpal epithelial branch and descending branch of carpal epithelial branch (P<0.05). There was no significant difference in the distance of pedicle from pisiform/lunate between branch of trunk of ulnar artery and recurrent branch of deep palmar branch (P>0.05), and between carpal epithelial branch and descending branch of carpal epithelial branch (P>0.05). But the differences between the other vascular pedicles were significant (P<0.05). ConclusionThere are abundant nutrient vessels at the proximal and ulnar sides of pisiform, so excessive stripping of the proximal and ulnar soft tissues should be avoided during the vascularized pisiform transfer. It is feasible to treat advanced Kienböck’s disease by pisiform transfer with the carpal epithelial branch of ulnar artery and the descending branch.
Objective To design customized titanium alloy lunate prosthesis, construct three-dimensional finite element model of wrist joint before and after replacement by finite element analysis, and observe the biomechanical changes of wrist joint after replacement, providing biomechanical basis for clinical application of prosthesis. Methods One fresh frozen human forearm was collected, and the maximum range of motions in flexion, extension, ulnar deviation, and radialis deviation tested by cortex motion capture system were 48.42°, 38.04°, 35.68°, and 26.41°, respectively. The wrist joint data was obtained by CT scan and imported into Mimics21.0 software and Magics21.0 software to construct a wrist joint three-dimensional model and design customized titanium alloy lunate prosthesis. Then Geomagic Studio 2017 software and Solidworks 2017 software were used to construct the three-dimensional finite element models of a normal wrist joint (normal model) and a wrist joint with lunate prosthesis after replacement (replacement model). The stress distribution and deformation of the wrist joint before and after replacement were analyzed for flexion at and 15°, 30°, 48.42°, extension at 15°, 30°, and 38.04°, ulnar deviation at 10°, 20°, and 35.68°, and radial deviation at 5°, 15°, and 26.41° by the ANSYS 17.0 finite element analysis software. And the stress distribution of lunate bone and lunate prosthesis were also observed. Results The three-dimensional finite element models of wrist joint before and after replacement were successfully constructed. At different range of motion of flexion, extension, ulnar deviation, and radial deviation, there were some differences in the number of nodes and units in the grid models. In the four directions of flexion, extension, ulnar deviation, and radial deviation, the maximum deformation of wrist joint in normal model and replacement model occurred in the radial side, and the values increased gradually with the increase of the range of motion. The maximum stress of the wrist joint increased gradually with the increase of the range of motion, and at maximum range of motion, the stress was concentrated on the proximal radius, showing an overall trend of moving from the radial wrist to the proximal radius. The maximum stress of normal lunate bone increased gradually with the increase of range of motion in different directions, and the stress position also changed. The maximum stress of lunate prosthesis was concentrated on the ulnar side of the prosthesis, which increased gradually with the increase of the range of motion in flexion, and decreased gradually with the increase of the range of motion in extension, ulnar deviation, and radialis deviation. The stress on prosthesis increased significantly when compared with that on normal lunate bone. Conclusion The customized titanium alloy lunate prosthesis does not change the wrist joint load transfer mode, which provided data support for the clinical application of the prosthesis.
ObjectiveTo evaluate the long-term effectiveness of lunate excision and vascularized capitate osteotomy transposition for advanced Kienböck's disease. MethodsBetween June 2004 and January 2008,16 patients with Kienböck disease in Lichtman stages ⅢB-IV were treated with lunate excision and vascularized capitate osteotomy transposition.There were 10 males and 6 females at the age of 27-59 years (mean,38.8 years).The disease was caused by trauma in 10 cases,and unknown reason in 6 cases.The main clinical symptoms were pain and limited activity of the wrist joint,and the disease duration was 5-32 months (mean,26.5 months).The carpal height index was 0.88±0.05; the radioscaphoid angle was (63.8±9.1)°.The visual analogue scale (VAS) score,range of motion (ROM),grip strength,Evans score,and radiographic changes were used to assess the effectiveness during follow-up. ResultsAll patients obtained healing of incision by first intention and were followed up 5 years and 4 months to 9 years (mean,5.8 years).VAS score was 2.0±1.5 at the final follow-up.The ROM of the flexion and extension of the wrist joint at the affected side were significantly less than those at the normal side (P<0.05).However,no significant difference was found in the grip strength and Evans score between the affected side and normal side (t=-0.997,P=0.327; t=-1.852,P=0.077).Postoperative radiographs showed that the carpal height index was 0.94±0.03,and the radioscaphoid angle was (48.4±4.8)°,which were improved significantly when compared with preoperative ones (t=-3.927,P=0.000; t=5.987,P=0.000).Osteophyte at the dorsal side of the radius and scaphoid rotation occurred in 6 cases and 2 cases,respectively. ConclusionLunate excision and vascularized capitate osteotomy transposition is a reliable method for advanced Kienböck's disease,with favorable improvement in wrist pain and grip strength for long-term follow-up.
Objective To investigate the long-term effectiveness of Ni-Ti memory alloy tripod fixator in the treatment of Kienböck disease. Methods The clinical data of 22 patients with Kienböck disease who were treated with Ni-Ti memory alloy tripod fixator between January 2011 and September 2013 and followed up more than 10 years was retrospectively analyzed. There were 14 males and 8 females with an average age of 45 years (range, 20-64 years). The Lichtman staging was stage Ⅲb. According to AO/Association for the Study of Internal Fixation (AO/ASIF) classification, there were 6 cases of type B1, 2 cases of type B2, 10 cases of type B3, and 4 cases of type C2. The disease duration ranged from 18 to 50 months, with an average of 30.7 months. The operation time, intraoperative blood loss, and complications were recorded. Wrist height ratio and scapholunate angle were measured by wrist anteroposterior and lateral X-ray films before and after operation. The grip strength of bilateral hands was measured by Jamar dynamometer. The wrist pain was evaluated by visual analogue scale (VAS) score, and the wrist function was evaluated by Mayo score, and the radial deviation, ulnar deviation, dorsiflexion, and palmar flexion range of motion of wrist were measured. Results The operation time was 45-60 minutes, with an average of 52.21 minutes; the intraoperative blood loss was 50-60 mL, with an average of 58.63 mL. No nerve or blood vessel injury occurred during operation. All patients were followed up 10-13 years (mean, 11.3 years). X-ray films at 3 months after operation showed that the density of lunate bone was lower than that before operation. Satisfactory fusion of the scapho-trapezio-trapezoeid joint was achieved at 3-6 months after operation (mean, 4.5 months), and the wrist height ratio and the scapholunate angle after fusion significantly improved when compared with those before operation (P<0.05). Wrist pain relieved, scaphoid rotation and dislocation improved, and no radiocarpal joint degeneration was found during follow-up, and no internal fixator loosening, breakage, or lunate bone necrosis occurred. At last follow-up, the wrist radial deviation, ulnar deviation, dorsiflexion, and palmar flexion range of motion, VAS score, and grip strength of the affected side significantly improved when compared with those before operation (P<0.05); the grip strength of the affected side recovered to 99.00%±1.25% of the healthy side. Mayo score ranged from 72 to 93, with an average of 85; 14 cases were rated as excellent, 5 good, and 3 satisfactory, the excellent and good rate was 86.4%. ConclusionIn the treatment of stage Ⅲb Kienböck’s disease, the scapho-trapezio-trapezoeid joint usion using Ni-Ti memory alloy tripod fixator can effectively reduce pain, improve hand function, and prevent further deterioration, and achieve good long-term effectiveness.