Carpal impaction with the ulnar styloid process: treatment with partial styloid resection

Carpal impaction with the ulnar styloid process (stylocarpal impaction) occurs less frequently than with the ulnar head (ulnocarpal impaction), and more commonly develops in wrists with negative ulnar variance. Physical examination, radiographic evaluation, and wrist arthroscopy are all helpful in excluding alternative causes of ulnar wrist pain. When an ulnocarpal stress test elicits pain, and radiographs suggest that this is due to carpal impaction with the ulnar styloid, partial resection of the styloid process provides successful treatment, so long as the insertion of the triangular fibrocartilage at the base of the styloid is not disrupted.     

Evaluation of ulnar styloid length

PURPOSE: General awareness of the ulnar styloid impaction syndrome is low and often is neglected. Radiographic evaluation of the ulnar styloid length generally includes an x-ray of the posteroanterior view. This study analyzed the effect of different radiographic views to assess the length of the ulnar styloid. The ulnar styloid-capitate ratio (SCR) expresses the relative length of the ulnar styloid, and we compare this ratio with the ulnar styloid process index (USPI). METHODS: To evaluate the ulnar styloid and to analyze the effect of different radiographic views on measurement outcome, measurements were performed in 7 different radiographic positions of both wrists of 69 patients. To assess the relative size of the ulnar styloid and its impaction potential the USPI was calculated, re-evaluated, and compared with the SCR, in which the length of the ulnar styloid is divided by the length of the capitate bone. RESULTS: The mean ulnar styloid length in all standard posteroanterior radiographs is 4.4 +/- 1.2 mm. In our population the average USPI was 0.21 +/- 0.11 and the average SCR was 0.18 +/- 0.05. The SCR has a stronger correlation with the length of the ulnar styloid than the USPI. Furthermore this new ratio eliminates differences related to gender, whereas the USPI does not. CONCLUSIONS: To identify ulnar impaction potential we recommend using the USPI, but to compare ulnar styloid between patients we recommend using the SCR obtained from neutral posteroanterior radiographs. For white patients we suggest defining a long ulnar styloid as having an SCR greater than 0.18 +/- 0.05 and/or an overall styloid length greater than 6 mm.     

Positive or Negative Ulnar Variance after Ulnar Shortening for Ulnar Impaction Syndrome: A Retrospective Study

Background

The goal of this study was to compare simple radiographic findings and clinical results according to residual ulnar variance following ulnar shortening for ulnar impaction syndrome.

Methods

Forty-five cases of ulnar impaction syndrome, which were treated with ulnar shortening from 2005 to 2008, were studied retrospectively. Group I included 13 cases with positive residual variance after ulnar shortening and group II included 32 cases with negative variance after shortening. The presence of a lunate cystic lesion both preoperatively and at final follow-up and assessments of wrist function based on the modified Mayo wrist score, the disabilities of the arm, shoulder, and hand (DASH) score, as well as the Chun and Palmer score were evaluated.

Results

A cystic lesion of the lunate was present in 4 cases preoperatively and the size decreased in 2 cases at final follow-up in group I, and in 10 and 5 cases, respectively, in group II. No statistical difference was observed between the groups. The modified Mayo wrist score, DASH score, as well as the Chun and Palmer score improved significantly in both groups. No significant differences were observed between the two groups in terms of the proportion of positive cystic lesions at final follow-up or the functional scores.

Conclusions

After ulnar shortening, the degree of radiological change in the cystic lunate lesions and clinical improvement did not differ significantly between the groups with unintended residual positive and negative variance after shortening.     

MSCT图像重建技术在尺骨撞击综合征中的应用

目的评价MSCT图像重建技术在尺骨撞击综合征诊断中的应用价值。方法回顾性分析经腕关节镜检查证实的18例尺骨撞击综合征患者MSCT图像重建技术及标准后前位X线平片检查的影像资料,对尺骨变异、月骨及三角骨异常变化进行统计学分析。结果⑴MSCT图像重建技术及标准后前位X线平片检查测量出的尺骨变异差异无统计学意义(t=0.3562,P>0.05);⑵MSCT图像重建显示18例尺骨阳性变异15例,占总例数83.3%,其中阳性变异超过2 mm者11例,占总阳性变异的73.3%;中性及阴性变异3例,占总例数16.7%;⑶MSCT重建技术显示月骨和/或三角骨异常变化14例,占总例数77.8%,其中单纯月骨异常变化8例,月骨及三角骨同时异常变化5例,单纯三角骨异常变化1例。标准后前位X线平片能显示月骨和/或三角骨异常变化10例,占总例数55.6%,其中单纯月骨异常变化6例、月骨及三角骨同时异常变化4例,无单纯三角骨异常变化;⑷MSCT图像重建技术测量尺骨阳性伴月骨及三角骨异常变化14例,占总例数77.8%,尺骨阳性变异不伴月骨及三角骨异常变化1例,占总例数5.6%。阳性变异大于2 mm伴月骨及三角骨异常变化11例,占总例数61.1%,月骨及三角骨异常变化例数的78.6%。无尺骨中性及阴性变异伴月骨及三角骨异常变化。结论MSCT图像重建技术及后前位X线平片测量尺骨变异无统计学差异;尺骨撞击综合征发展过程中尺骨阳性变异呈易感因素;尺骨阳性变异大于2 mm时易引起月骨、三角骨异常变化;MSCT图像重建技术可以很好地显示尺骨变异及月骨、三角骨骨质硬化情况。     

非创伤性尺腕撞击综合征的诊断和治疗

目的 探讨无明确创伤病史且X线片表现不典型的尺腕撞击综合征的特点及诊断标准和治疗方法.方法 回顾性研究2003年10月至2010年10月明确诊断和治疗的55例尺腕撞击综合征患者中没有明确创伤病史且X线片表现不典型的25例,在Kostas诊断标准基础上,观察尺腕压力试验、动态尺骨正向变异、MRI检查的阳性率和腕关节镜检查,分析观察指标对诊断结果的影响和临床意义.治疗采取尺骨短缩手术,截骨方式中16例采用水平截骨(Darrow法),9例采用斜行截骨(Rayhack法),加压钢板螺钉内固定.采用Darrow标准作为疗效评价标准.结果 本组25例患者中尺腕压力试验阳性比率为84％,动态尺骨正向变异的发生比率为52％,MRI检查发现腕骨信号改变的比率为82％,以月骨尺侧部近端和三角骨腰部最为常见,腕关节镜检查三角纤维软骨复合体(TFCC)退变及尺骨头和月骨的软骨退变比率为100％.随访时间4～48个月,平均26个月.25例骨折均愈合,水平截骨的平均愈合时间为4.5个月,斜行截骨的平均愈合时间为2.5个月.优7例,良15例,中2例,差1例;总优良率为88％.术后未发生严重并发症,治疗结果满意.结论 非创伤性尺腕撞击综合征由于缺少明确的创伤病史,尤其当X线片表现不典型时同其他引起腕关节尺侧疼痛的病因较难鉴别,应用尺腕压力试验、动态尺骨正向变异检查和早期MRI检查可早期明确诊断,有效提高诊断率.腕关节镜检查可作为诊断困难和鉴别诊断的补充手段.应用尺骨短缩手术可明显改善症状,斜行截骨是值得推荐的截骨方式.     

Ulnar impaction

Ulnar impaction syndrome is a common source of ulnar-sided wrist pain. It is a degenerative condition that occurs secondary to excessive load across the ulnocarpal joint, resulting in a spectrum of pathologic changes and symptoms. It may occur in any wrist but is usually associated with positive ulnar variance, whether congenital or acquired. The diagnosis of ulnar impaction syndrome is made by clinical examination and is supported by radiographic studies. Surgery is indicated if nonoperative treatment fails. Although a number of alternatives exist, the 2 primary surgical options are ulnar-shortening osteotomy or partial resection of the distal dome of the ulna (wafer procedure). This article discusses the etiology of ulnar impaction syndrome, and its diagnosis and treatment.     

Ulnocarpal impaction syndrome restricts even midcarpal range of motion.

Ulnocarpal impaction syndrome is believed to be caused by abutment between the ulna and the ulnar carpus. We measured radiocarpal and midcarpal ranges of motion in 40 patients with ulnocarpal impaction syndrome by radiographic motion studies. The results showed that the radiocarpal and midcarpal ranges of motion were equally restricted in the affected wrist compared with the unaffected wrist. Therefore, motion of the radiocarpal joint and midcarpal joint contributed equally to total wrist motion bilaterally. No correlation between ulnar variance and the contribution of radiocarpal motion to overall wrist motion was found. Restriction of wrist motion in ulnocarpal impaction syndrome is not caused directly by abutment between the ulna and ulnar carpus, but a satisfactory explanation for restricted motion is still lacking.     

Anatomic and biomechanical analysis of the arthroscopic wafer procedure.

The ulnar impaction syndrome is a common clinical entity that is most often associated with positive ulnar variance and is characterized by triangular fibrocartilage complex (TFCC), lunate, and/or distal ulnar pathology. Traditional treatment for symptomatic ulnar impaction syndrome has been conservative; however, in cases refractory to nonoperative management, formal ulnar shortening has been successful in long-term clinical series. Recently, arthroscopic ulnar shortening, the "arthroscopic wafer procedure" (AWP) (debridement of the perforated TFCC margins and limited ulnar head resection using a motorized burr) has become an option to treat this clinical syndrome. In an attempt to evaluate the biomechanical efficacy of the AWP, an experimental study was undertaken using nine ulnar positive cadaver forearms. Each specimen was evaluated biomechanically using axial load cells and pressure-sensitive film to evaluate the effect of serial resection of the TFCC and distal ulna on axial load and ulnar carpal pressures. The results of this experimental study revealed a statistically significant unloading of the ulnar aspect of the wrist after excision of the centrum of the TFCC and resection of the radial two-thirds width of the ulnar head, to a depth of subchondral bone resection. Furthermore, additional bony resection tended to correlate favorably with the stage of TFCC pathology noted, i.e., the more advanced the stage, the more resection necessary to unload the ulnar aspect of the wrist. Based on this biomechanical study, a limited clinical series has been initiated with early favorable results. The AWP biomechanically unloads the ulnar carpal complex, and therefore has a theoretical potential of relieving the symptoms of the ulnar impaction syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)     

Arthroscopic treatment of ulnar impaction syndrome

Ulnar impaction syndrome occurs in the setting of a central traumatic or degenerative defect in the triangular fibrocartilage complex in patients with ulnar positive variance. Chondral and subchondral edema, mechanical impingement of the articular disc, and chondromalacia of the distal ulna, proximal lunate, and proximal triquetrum produce symptoms with activity that do not improve with rest. Decreasing ulnocarpal load-sharing across the wrist with recession of the distal ulna is necessary to relieve symptoms in the majority of patients. Arthroscopic treatment with triangular fibrocartilage complex debridement and arthroscopic ulnar wafer resection is an effective treatment for ulnar impaction syndrome. It affords a single-stage, minimally invasive approach, with similar efficacy and fewer complications than open wafer resection or ulnar shortening osteotomy.     

Long-term Outcomes of Ulnar Shortening Osteotomy for Idiopathic Ulnar Impaction Syndrome: At Least 5-Years Follow-up

Background

There have been few outcomes studies with follow-up after performing ulnar shortening osteotomy for ulnar impaction syndrome. We investigated the long-term clinical and radiological outcomes of ulnar shortening osteotomy for the treatment of idiopathic ulnar impaction syndrome.

Methods

We retrospectively reviewed 36 patients who had undergone ulnar shortening osteotomy for idiopathic ulnar impaction syndrome for a mean follow-up of 79.1 months (range, 62 to 132 months). The modified Gartland and Werley scores were measured pre- and postoperatively. The radiographic parameters for the assessment of the distal radioulnar joint (DRUJ) as well as the relationship between these radiographic parameters and the clinical and radiological outcomes were determined.

Results

The average modified Gartland and Werley wrist score improved from 65.5 ± 8.1 preoperatively to 93.4 ± 5.8 at the last follow-up visit. The average preoperative ulnar variance of 4.7 ± 2.0 mm was reduced to an average of -0.6 ± 1.4 mm postoperatively. Osteoarthritic changes of the DRUJ were first seen at 34.8 ± 11.1 months follow-up in 6 of 36 wrists (16.7%). Those who had osteoarthritic changes in the DRUJ had significantly wider preoperative ulnar variance, a longer distal radioulnar distance and a greater length of ulnar shortening, but the wrist scores of the patients who had osteoarthritic changes in the DRUJ were comparable to those who did not have osteoarthritic changes in the DRUJ.

Conclusions

The clinical outcomes are satisfactory for even more than 5 years after ulnar shortening osteotomy for treating idiopathic ulnar impaction syndrome despite the osteoarthritic changes of the DRUJ. The patients who need a larger degree of ulnar shortening may develop DRUJ arthritis.     

Arthroscopic treatment of the ulnar impaction syndrome

The ulnar impaction syndrome is due to hyperpressure in the ulnocarpal joint. It occurs most frequently following distal radial fractures with shortening, but can also be secondary to a primitive length discrepancy between a short radius and a long ulna (positive ulnar variance). Symptoms and clinical findings, even though characteristic, are not specific. Standard X rays show a positive ulnar variance, and sometimes a hyperpressure cyst in the lunate. CT arthroscan and MRI studies demonstrate indirect signs of hyperpressure. If medical treatment fails to improve the condition, the choice surgical technique is arthroscopic, allowing debridement of the TFCC central tear, and shortening of the horizontal aspect of the ulnar head.     

Ulnar shortening osteotomy in idiopathic ulnar impaction syndrome

BACKGROUND: Idiopathic ulnar impaction syndrome can be defined as a degenerative condition of the ulnar aspect of the wrist in patients with congenital or dynamic positive ulnar variance without a history of fracture or premature physeal arrest. The purpose of this study was to evaluate the clinical features of idiopathic ulnar impaction syndrome and the outcomes of ulnar shortening osteotomy for this group of patients. METHODS: Thirty-one wrists in twenty-nine patients with idiopathic ulnar impaction syndrome were treated with an ulnar shortening osteotomy. Ulnar variance was measured on an anteroposterior radiograph of the wrist, and radioulnar distance was measured on a lateral radiograph, with the forearm in neutral rotation, to evaluate any displacement of the ulnar head from the distal aspect of the radius. All patients were followed clinically and radiographically for a mean of thirty-two months. RESULTS: An average preoperative ulnar variance of +4.6 mm (range, 2 to 7.5 mm) was reduced to an average of -0.7 mm (range, -4 to +1 mm) postoperatively. Preoperatively, the modified Gartland and Werley score was an average (and standard deviation) of 69.5 +/- 7.6, with twenty-four wrists rated poor and seven rated fair. Postoperatively, the score improved to an average of 92.5 +/- 8.0, with twenty-four wrists rated excellent; five, good; one, fair; and one, poor. Dorsal subluxation of the distal aspect of the ulna was found concomitantly in nine wrists, and it was found to be reduced by the shortening osteotomy. Seven patients had cystic changes in the carpal bones preoperatively, but these were not evident one to two years after the operation. CONCLUSIONS: Ulnar shortening osteotomy improved wrist function in patients with idiopathic ulnar impaction syndrome and reduced the subluxation of the distal radioulnar joint, which is commonly found in these patients. Degenerative cystic changes of the ulnar carpal bones appear to resolve following the shortening osteotomy.     

Lunate subchondral cysts: Are there specific radiologic findings for patients with symptomatic ulnocarpal impaction?

BackgroundThere are few clinical studies evaluating the relationship between lunate cysts and symptomatic ulnar impaction syndrome (UIS). The purpose of this study was to investigate the prevalence and relationship between lunate cysts and UIS by comparing data from patients with UIS against those without.Materials and methodsFrom March 2012 to January 2015, 375 patients who had undergone MRI or CT for reasons other than ulnar-sided wrist pain were classified into the ‘asymptomatic group’ (Group I). Thirty three patients who had been diagnosed with UIS were classified in the ‘UIS group’ (Group II). We determined whether any differences were present between the two groups and evaluated prognostic factors for lunate cysts.ResultsThe prevalence of lunate cysts was significantly higher in Group II but only reached just above 50% (10.4% vs. 57.6%, p < 0.001]. Dorsal-side lunate cysts were more frequent than palmar side in Group I, while Group II had more cysts on the palmar side (74.4% vs. 52.6%, p = 0.001). Logistic regression analysis revealed that UIS and patient age was a significant factor for the presence of lunate cysts (odds ratio: 11.692, p < 0.001; odds ratio: 1.063, p < 0.001, respectively). However, positive ulnar variance or duration of symptom in Group II was not a predisposing factor for lunate cysts (odds ratio: 1.035, p = 0.598; odds ratio: 1.007, p = 0.877, respectively).ConclusionSince positive ulnar variance or duration of symptom did not affect the formation of the lunate cyst and only slightly more than 50% (57.6%) of patients with UIS had a lunate cyst, it seems unlikely that these cysts are a pathognomonic finding. Surgeons can obtain some evidence from lunate cysts on radiographic exams, but care must be taken that this diagnosis is not made hastily or without due consideration.     

The importance of the pronated grip x-ray view in evaluating ulnar variance

Although dynamic increases in ulnar variance may accompany functional activity, radiographic assessment of ulnar variance traditionally has used a neutral rotation x-ray of the wrist that provides an image of the radioulnar length with the wrist unloaded. Such a view may underestimate variance in wrists in which power grip and pronation result in significant proximal migration of the radius. This study investigates the effect of a maximum grip effort in combination with forearm pronation on ulnar variance in 22 patients who presented with ulnar wrist pain. The pronated grip x-ray view resulted in statistically significant increases in ulnar variance. Preoperative ulnar variance should be measured using both neutral rotation and pronated grip x-rays before selecting treatment for causes of ulnar wrist pain that are affected by radioulnar length so that dynamic increases in ulnar variance are considered when operative treatment is necessary.     

尺骨撞击综合征的特点及早期诊断

目的探讨尺骨撞击综合征的特点及早期诊断方法并提出新的诊断标准。方法对1998年12月～2004年12月治疗的123例腕尺侧疼痛患者进行仔细检查,采用顾玉东等提出的诊断标准,特别结合腕部MRI检查,确诊尺骨撞击综合征48例。总结尺骨憧击综合征的X线及MRI影像学特点,分析腕部临床症状与Chun和Palmer评分及影像学表现的关系。结果本组33例患者存在尺骨阳性变异(68．8%),X线检查发现患者出现腕骨坏死比例为27．1%,其中以月骨坏死为主(64．7%)；MRI检查均发现腕骨不同程度信号改变,腕部骨坏死均位于月骨尺侧部分的近端和三角骨腰部及底部；患者腕部临床症状与Chun和Palmer评分及影像学表现关系密切。结论提高对尺骨撞击综合征的认识水平,以临床症状为基础,充分利用影像学检查,特别是MRI检查,可以明显提高该病征的早期诊断率。     

Radiographic changes in wrists with ulnar plus variance observed over a ten-year period

This study provides additional radiographic information concerning the long-term effect of ulnar impingement. Films of 198 wrists of 102 patients with vibration disease observed over ten or more years were reviewed. All the wrists showed ulnar plus variance of more than 0 mm except seven. Degenerative changes were found in 58 wrists and were seen only on the ulnar side of the wrist, especially in the ulnoproximal area of the lunate. Most of the degenerative changes in the wrists with ulnar plus variance had progressed or changed during the ten or more years. Ulnar plus variance may play an important role in inducing or causing progression of degenerative change in the wrist.     

Ulnar nerve paresis secondary to lunate dislocation

A volar dislocation of the lunate is a severe injury associated with rupture of the palmar capsule usually occurring as a triad with radial styloid and transcaphoid fractures. Associated median nerve palsy can occur due to palmar rotation of the dislocated lunate into the carpal tunnel, but ulnar nerve dysfunction is rare. We present the second reported case of ulnar nerve paresis secondary to lunate dislocation resulting from a wrist hyperextension injury. Early open reduction and screw fixation lead to rapid resolution of symptoms.     

Results of ulnar shortening osteotomy for ulnocarpal impaction syndrome in wrists with neutral or negative ulnar variance

Ulnocarpal impaction syndrome was diagnosed in six wrists of five patients with neutral or negative ulnar variance. All underwent ulnar shortening with satisfactory results. The average grip strength increased from 53% to 78% and the range of flexion-extension increased from 82% to 93%, the mean Cooney's score improved from 25 to 83. These cases show that ulnocarpal impaction syndrome can occur in wrists with zero or negative ulnar variance, and that ulnar shortening is an effective treatment for such wrists.     

Unusual volar dislocation of the lunate into the distal forearm: case report

A case of a severe wrist injury (fractures of the scaphoid, capitate, hamate, and ulnar styloid process) with volar dislocation of the lunate into the soft tissues of the forearm is presented. This degree of displacement of the lunate is exceedingly rare, and we believe has not been previously reported. Possible mechanisms, hyperextension injury forcing the lunate forward out of the carpus, or contact between the volar wrist skin surface and another object or surface propelling the dislocated lunate into the forearm, are discussed.