Biaxial total wrist arthropla

Arthrodesis is a reliable and predictable method of treating patients with symptomatic radiocarpal joint destructionand should be recommended in most cases. However, some patients are not able to compensate for the lack of wrist mobility associated with wrist fusion because of multiple joint arthroses as are commonly seen in patients with rheumatoid arthritis. For these patients, total wrist arthroplasty is best described as a higher risk and higher reward procedure. A recent review of 64 cases of total wrist arthroplasty found an 83% implant survival rate at a mean follow-up period of 6.5 years. Clinical results showed excellent patient satisfaction and very good pain relief and range of motion. Of the patients who failed arthroplasty and were eligible for revision total wrist arthroplasty, 80% elected revision arthroplasty over recommended arthrodesis. This report reviews patient selection, technique, postoperative management, management of complications, and expected outcome of biaxial total wrist arthroplasty.     

Universal 2 total wrist arthroplasty

The Universal 2 wrist replacement is considered my many to be the implant of choice in patients with inflammatory arthropathy requiring joint replacement. The procedure is discussed in this article and technical aspects considered.     

Patello-femoral joint in total knee replacement

Total knee arthroplasty (TKA) surgery is a widely used treatment and has a high success rate. Despite its success, the patello-femoral articulation has been overlooked as a contributor to the successful outcome of TKA. Patello-femoral complications remain the leading cause of failed knee replacement, accounting for up to 10% of complications. To understand the concept of patellar mal-tracking, we explore the normal anatomy and biomechanics of the patello-femoral articulation, and review the surgical factors and complications related to patellar tracking, with an aim to discussing the concepts on how to avoid such complications. Surgeons should be aware of the frequent occurrence of abnormal patellar tracking, and should pay particular attention to the patello-femoral component of knee replacement surgery.     

Proximal-distal shift of the center of rotation in a total wrist arthroplasty is more than twice of the healthy wrist

Reproduction of healthy wrist biomechanics should minimize the abnormal joint forces that could potentially result in the failure of a total wrist arthroplasty (TWA). To date, the in vivo kinematics of TWA have not been measured and it is unknown if TWA preserves healthy wrist kinematics. Therefore, the purpose of this in vivo study was to determine the center of rotation (COR) for a current TWA design and to compare its location to the healthy wrist. The wrist COR for six patients with TWA and 10 healthy subjects were calculated using biplane videoradiography as the subjects performed various range-of-motion and functional tasks that included coupled wrist motions. An open-source registration software, Autoscoper, was used for model-based tracking and kinematics analysis. It was demonstrated that the COR was located near the centers of curvatures of the carpal component for the anatomical motions of flexion-extension and radial-ulnar deviation. When compared to healthy wrists, the COR of TWAs was located more distal in both pure radial deviation (P < .0001) and pure ulnar deviation (P = .07), while there was no difference in its location in pure flexion or extension (P = .99). Across all coupled motions, the TWA's COR shifted more than two times that of the healthy wrists in the proximal-distal direction (17.1 vs 7.2 mm). We postulate that the mismatch in the COR location and behavior may be associated with increased loading of the TWA components, leading to an increase in the risk of component and/or interface failure.     

Pisiform impingement after total wrist arthroplasty

We present a 64-year-old woman with rheumatoid arthritis who developed increasing pain 3 years after a total wrist arthroplasty. The pain was localized over the ulnar side of the wrist secondary to erosion of the pisiform. Pisiform excision resulted in a resolution of the symptoms. When placing a carpal component, which includes a base plate as part of its design, care should be taken to avoid any overhang of the implant edge into the pisotriquetral joint.     

Colles骨折与腕关节不稳定

目的探讨Colles骨折合并腕关节不稳定的发生机制和防治措施。方法对53例Colles骨折随访3～5年,测量其复位前、后和去除外固定后的腕关节正、侧位平片,并测定腕关节功能的主、客观指标。比较合并与不合并腕关节不稳定两组的功能恢复情况。结果伴有腕关节不稳定的发生率为41.5%(22/53),其中腕背不稳定（DISI）10例（45.5%）,舟月分离12例（54.5%）,多发生在严重骨折移位,高能量损伤的患者。骨折愈合后,合并腕关节不稳定的功能明显差于单纯Colles骨折患者。结论对骨折移位严重或高能量损伤的Colles骨折,要注意是否合并腕关节不稳定。对合并腕关节不稳定的Colles骨折,复位时应尽可能恢复掌倾角,如骨折稳定,腕关节固定在中立位或轻度背伸位（＜10°）为宜;如骨折不稳定,应固定在掌屈尺偏位,2周后改为固定于中立位或轻度背伸位（＜10°）,以防止远期出现腕关节不稳定。     

Innervation of the wrist joint and surgical perspectives of denervation

PURPOSE: Because our experience with the techniques used in denervation surgery of the wrist joint often has proven insufficient in treating chronic pain we conducted an anatomic study to clarify the exact contributions of the nerves supplying the wrist joint. Our goal was to reveal all periosteal and capsular nerve connections and if necessary adjust our technique used in denervation surgery. METHODS: Innervation of the wrist joint was investigated by microdissection and histologic examination of 18 human wrists. An acetylcholinesterase method was used to identify the nerves, both in whole-mount preparations and in sections. RESULTS: We found that the main innervation to the wrist capsule and periosteal nerve network came from the anterior interosseous nerve, lateral antebrachial cutaneous nerve, and posterior interosseous nerve. The palmar cutaneous branch of the median nerve, the deep branch of the ulnar nerve, the superficial branch of the radial nerve, and the dorsal branch of the ulnar nerve also were found to have connections with the capsule. The periosteal nerve branches did not appear to play a major role in the innervation of the capsule and ligaments; here the specific articular nerve branches proved more important. The posterior and medial antebrachial cutaneous nerves did not connect to the wrist capsule or periosteum but rather terminated in the extensor and flexor retinaculum. CONCLUSIONS: Based on our findings we propose to denervate the wrist by making 2 incisions. With one palmar and one dorsal incision it should be possible to disconnect the periosteum from the capsule and interrupt the majority of the capsular nerve branches.     

Severity of scapholunate instability is related to joint anatomy and congruency

PURPOSE: To determine whether the bony architecture of the distal radius and proximal scaphoid have a role in stabilizing the scaphoid, and to determine whether a relationship between the bony geometry measurements and the amount of wrist constraint could be determined. METHODS: Eight cadaver wrists were tested in a wrist joint motion simulator. The level of scapholunate instability after sectioning the scapholunate interosseous, radioscaphocapitate, and the scaphotrapezium ligaments was determined and related to radiographic measurements of volar tilt, lateral tilt (ulnar tilt of the radioscaphoid fossa), the depth of the radioscaphoid fossa, and 6 radii of curvature measurements of the proximal scaphoid and distal radius. The force to dorsally dislocate the scaphoid out of the radioscaphoid fossa was computed. RESULTS: The radioscaphoid fossa and scaphoid curvatures were larger in those wrists that did not show gross instability after ligamentous sectioning in the wrist simulator. Similarly, those wrists with a deeper radioscaphoid fossa and greater volar tilt were also more stable. The force required to dislocate these wrists was greater than in those wrists that showed gross carpal instability. CONCLUSIONS: This study suggests that the bony anatomy of the radius and scaphoid have a role in stabilizing the carpus after ligament injury. The effect of ligament sectioning on producing carpal instability may be moderated by the bone geometry of the radiocarpal joint. This may explain why some people may have a tear of the scapholunate interosseous ligament but not present with clinical symptoms.     

Patellar tendon rupture and marked joint instability after total knee arthroplasty

Background Patellar tendon rupture is a rare complication of total knee arthroplasty (TKA). Multiple repair methods have been described in the literature. Methods A 66-year-old woman suffered a patellar tendon re-rupture and marked joint instability within 6 months after revision TKA. She underwent re-revision TKA and extensor mechanism reconstruction with femoral quadriceps tendon and augmentation by a Leeds-Keio ligament. Result It was fairly difficult to acquire a satisfactory range of motion as well as gain in knee extension capacity by eliminating the extension lag. Conclusion Patellar tendon ruptures after TKA should be repaired as soon as they are recognized.     

New concept for total wrist replacement

Wrist prostheses have never achieved the sort of clinical outcomes found with those of hips and knees. We have developed a novel uncemented modular wrist prosthesis with screw fixation, metal-on-metal coupling, and ball-and-socket articulation. Eight patients admitted for wrist arthrodesis to treat primary or secondary osteoarthritis (not rheumatoid) were operated on. The prosthesis reduced the amount of bone removed and spared the distal radioulnar joint. After 7 to 9 years we found that the fixed centre of the ball-and-socket articulation provided good stability and mobility, and relief of pain and grip strength were satisfactory. We saw no luxations, metacarpal fractures or cut-outs, or mechanical failures of the implants. Two distal screws loosened (revised with new distal screws), and one early inflammation and one late infection occurred (revised to arthrodesis). We propose modifications to the implant with reduction in the diameter of the screws and the height of the threads, and rounding of the distal tip. The technique should include release of the third carpometacarpal joint, alignment of the capitate and the third metacarpal, and arthrodesis of the joint with bone chips.     

Risk factors for periprosthetic joint infection following total ankle replacement

BackgroundIdentifying preoperative patient characteristics that correlate with an increased risk of periprosthetic joint infection (PJI) following total ankle replacement (TAR) is of great interest to orthopaedic surgeons, as this may assist with appropriate patient selection. The purpose of this study is to systematically review the literature to identify risk factors that are associated with PJI following TAR.MethodsUtilizing the terms “(risk factor OR risk OR risks) AND (infection OR infected) AND (ankle replacement OR ankle arthroplasty)” we searched the PubMed/MEDLINE electronic databases. The quality of the included studies was then assessed using the AAOS Clinical Practice Guideline and Systematic Review Methodology. Recommendations were made using the overall strength of evidence.ResultsEight studies met the inclusion criteria. A limited strength of recommendation can be made that the following preoperative patient characteristics correlate with an increased risk of PJI following TAR: inflammatory arthritis, prior ankle surgery, age less than 65 years, body mass index less than 19, peripheral vascular disease, chronic lung disease, hypothyroidism, and low preoperative AOFAS hindfoot scores. There is conflicting evidence in the literature regarding the effect of obesity, tobacco use, diabetes, and duration of surgery.ConclusionsSeveral risk factors were identified as having an association with PJI following TAR. These factors may alert surgeons that a higher rate of PJI is possible. However, because of the low level of evidence of reported studies, only a limited strength of recommendation can be ascribed to regard these as risk factors for PJI at this time.     

腕关节色素绒毛结节性滑膜炎误诊1例

1　临床资料患者 ,女 ,5 0岁。 1995年无意中发现右腕尺背侧有一包块 ,蚕豆大小 ,无疼痛 ,不影响腕关节活动 ,当时未就诊。此后肿块缓慢生长 ,1年后增大约1倍 ,在当地乡镇医院诊断为腱鞘囊肿 ,未治疗。 2 0 0 0年 8月 2 0日 ,因肿块显著增大 ,且右腕胀痛来院就诊。检查 :右腕尺背侧有一 5ｃｍ× 3ｃｍ× 1ｃｍ大小肿块 ,外形不规则 ,局部肤色正常 ,质软 ,能活动 ,尺骨茎突处压痛 ,腕关节活动无明显异常。Ｘ线片检查未见明显异常 ,超声检查示右腕关节尺侧有一实性包块 ,边界清晰 ,形态不规则 ,内回声不均匀。诊断为脂肪瘤。2天后行肿块切除术…     

The effect of wrist surgery on the kinematic consistency of joint axis reconstruction in a static posture

Three‐dimensional analysis of wrist motion is a growing focus in orthopedic research, however, our understanding of its validity (accuracy and reliability) remains limited. Nine human cadavers were tested to estimate wrist joint axes alignment in a postural static pose. The objective was to investigate a rater's ability to reliably align three skin‐ tracked wrist joint coordinate system (WJCS) definitions across baseline and reconstructive wrist states (intact, mid‐carpal arthrodesis, and proximal‐row carpectomy). Two WJCSs (legacy, anatomic) were based on palpated bony landmarks and the third (functional) was based on both landmarks and passive flexion‐extension motion. A coordinate frame based on the anatomic definition was tracked with bone pins and served as a reference. Each WJCS was tested in each wrist state and in three forearm position (45° pronation, neutral, 45° supination). The angular offset about each axis of the WJCS frames were calculated with respect to the reference in flexion‐extension, radial‐ulnar deviation, and pronation‐supination for every iteration. Reliability and root mean square deviation values were analyzed across wrist states. Our data suggest that no WJCS is uniformly more reliable than another. The functional WJCS definition was most consistent across intact and post‐operative states for pronation‐supination offset, but this was dependent on rater interpretation. It still however offers the practical benefit of requiring fewer landmarks. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1341–1347, 2015.