Posteroanterior wrist radiography: importance of arm positioning

Proper interpretation of wrist radiography requires a standardized radiographic technique. We obtained posteroanterior (PA) radiographs of the wrist in nine patients in three different arm positions to study the effect of arm position on ulnar styloid process orientation. An appearance simulating a normal anteroposterior (AP) wrist radiograph was present in six of nine PA radiographs when the arm was positioned next to the trunk, and the elbow was flexed to a 90% angle. The orientation of the ulnar styloid was not helpful in differentiating either pronated from supinated wrist positions or AP from PA projections. We concluded that radiographic screening of the carpus should be performed with standardized wrist positioning and nomenclature as described in modern radiographic technological texts. Supplemental projections should be exposed and interpreted with an understanding of the position of the arm and the direction of the incident radiographic beam at the time of examination.     

Radiologic evaluation of the ulnar styloid.

The ulnar styloid (US) architecture was examined radiologically and directly by dissection in 13 cadaver wrists to examine a potential relationship between US shape and US abutment syndrome and to determine an optimal radiographic view that could be used to detect US fractures. A higher incidence of US abutment syndrome in the radially deviated US type was observed by dissection. Radiographs taken at varying shoulder abduction angles suggested that the base of the US and ulnar head are not round. To best evaluate the fovea and the US for possible US fractures, radiographs should be taken with the glenohumeral joint abducted 45 degrees, the elbow flexed 90 degrees, the forearm in neutral rotation, and the x-ray beam directed through the wrist perpendicular to the floor.     

Ulnar nerve excursion and strain at the elbow and wrist associated with upper extremity motion

Significant excursion of the ulnar nerve is required for unimpeded upper extremity motion. This study evaluated the excursion necessary to accommodate common motions of daily living and associated strain on the ulnar nerve. The 2 most common sites of nerve entrapment, the cubital tunnel and the entrance of Guyon's canal, were studied. Five fresh-frozen, thawed transthoracic cadaver specimens (10 arms) were dissected and the nerve was exposed at the elbow and wrist only enough to be marked with a microsuture. Excursion was measured with a laser mounted on a Vernier caliper fixed to the bone and aligned in the direction of nerve motion. A Microstrain (Burlington, VT) DVRT strain device was applied to the nerve at both the elbow and wrist. Nerve excursion associated with motion of the shoulder, elbow, wrist, and fingers (measured by goniometer) was measured at the wrist and elbow. An average of 4.9 mm ulnar nerve excursion was required at the elbow to accommodate shoulder motion from 30 degrees to 110 degrees of abduction, and 5.1 mm was needed for elbow motion from 10 degrees to 90 degrees. When the wrist was moved from 60 degrees of extension to 65 degrees of flexion, 13.6 mm excursion of the ulnar nerve was required at the wrist. When all the motions of the wrist, fingers, elbow, and shoulder were combined, 21.9 mm of ulnar nerve excursion was required at the elbow and 23.2 mm at the wrist. Ulnar nerve strain of 15% or greater was experienced at the elbow with elbow flexion and at the wrist with wrist extension and radial deviation. Any factor that limits excursion at these sites could result in repetitive traction of the nerve and possibly play a role in the pathophysiology of cubital tunnel syndrome or ulnar neuropathy at Guyon's canal.     

Fluoroscopically positioned radiographs of total shoulder arthroplasty

Between January 1990 and January 1991, 87 patients (100 shoulder arthroplasties) were radiographically examined with both standard and fluoroscopically positioned views. The sets of radiographs were compared and assessed for acceptability (the ability to interpret the interfaces), presence or absence of radiolucent zones, and differences between size and location of radiolucent zones. Fifty-six of the standard radiographs were unacceptable because of obliquity of the x-ray beam protection; only three localized views were unacceptable (p < 0.0001). Nineteen of the unacceptable standard views had radiolucent zones detected on the comparable fluoroscopic views. Forty-four radiographic sets were acceptable for evaluation. Of these, 27 sets had no differences; standard views showed the interface changes better in one, and localized views were better in 76 (p < 0.001). Thus in 68 of 100 total shoulder arthroplasties evaluated, clinical information that was not seen on standard radiographs was identified on fluoroscopic views. We conclude that fluoroscopic positioning is superior to standard radiographs in detecting implant-bone interface changes.     

Comparisons of three radiographic views in assessing for scapholunate instability

BackgroundMultiple wrist x-ray images have been described to assess for scapholunate (SL) instability. Some views may be redundant. The purpose of this study was to compare three plain x-ray views in identifying a traumatic diastasis of the SL interval.MethodsNineteen patients (19 wrists) with a positive scaphoid shift test and surgically confirmed SL ligament damage were identified. There were 15 males and 4 females with a mean age of 39 years. Pre-operative x-rays were reviewed, including posteroanterior (PA) neutral and PA ulnar deviation views of the injured wrist, and PA clenched fist views of the injured and uninjured wrists. Dynamic SL instability was defined by an SL mid-interval gap of <3 mm and static SL instability by a gap of ≥3 mm in the PA neutral views. The mid-interval measurements were compared between x-ray images.ResultsThere were 10 dynamic and 9 static SL instability cases. The PA ulnar deviation and the PA clenched fist views showed significantly greater SL gaps in comparison to the PA neutral views in dynamic but not static SL instability cases. In both categories of instability, there was no significant difference in the SL gaps between the two stress images. The PA clenched fist view of the uninjured wrist revealed SL gapping of >3 mm in 50% of patients but with generally greater gapping in the clenched fist view of the injured wrist.ConclusionsThe PA ulnar deviation and clenched fist stress views were equally effective in showing a dynamic SL diastasis following wrist injury. Neither view was more effective than a neutral PA view in diagnosing static SL instability.     

Posterior dislocation of the ulna at the elbow with associated fracture of the radial shaft

An exceptional case of posterior dislocation of the ulna at the elbow, associated with fracture of the radial shaft, is reported. Diagnosis was established with anteroposterior and lateral radiographs of the forearm, elbow and wrist. Treatment consisted of closed reduction of the ulnar dislocation and open reduction and internal fixation of the radius with an AO plate. A long arm cast was applied for 3 weeks with the elbow held at 90 °. Six months later full function of the limb had been achieved.     

Wrist-Spanning Fixation of Radiocarpal Dislocation: A Cadaveric Assessment of Ulnar Translation

Background: Radiocarpal dislocations represent a high-energy wrist injury that can occur with or without concomitant fractures about the wrist. Poor outcomes are often due to radiocarpal instability and secondary ulnar translation. The purpose of this cadaveric study is to determine if there is any difference in the radiographic parameters in a wrist dislocation model given the different location of distal fixation. Methods: Ten paired fresh cadaver upper extremities were fluoroscopically evaluated with posterior-anterior (PA) and lateral views. We created a radiocarpal dislocation model and applied a dorsal bridge plate to either the second or third metacarpal. Repeat PA and lateral fluoroscopic views were obtained for evaluation of radial inclination, radial height, volar tilt, ulnar variance, radiolunate angle, radioscaphoid angle, scapholunate angle, radial rotation index, and four indices for ulnar translation (Taleisnik, Gilula, McMurtry, and Chamay). Results: Bridge plate application to the second metacarpal resulted in a significantly greater incidence of ulnar translation compared to the third metacarpal. Application to either metacarpal resulted in extension of the carpus relative to the radius. Conclusions: A more anatomic radiocarpal relationship was restored more often when distal fixation of the dorsal wrist-spanning bridge plate was applied to the third metacarpal. Further investigation is warranted to determine clinical relevance of these findings in conjunction with clinical and radiographic outcomes.     

Residual subluxation of the elbow after dislocation or fracture-dislocation: treatment with active elbow exercises and avoidance of varus stress

During a 6-year period, 2 surgeons prescribed active elbow exercises and avoidance of shoulder abduction (varus stress) for 23 patients (15 men, 8 women) with a mean age of 43 years (range, 19-74 years) who had slight residual subluxation of a dislocated elbow after either nonoperative (3 simple dislocations and 2 fracture-dislocations) or operative treatment (18 fracture-dislocations). A stable elbow was achieved in all 23 patients, although 1 patient, treated late, had a very slight residual posterior subluxation of the radial head on radiographs. After a mean of 24 months (range, 12-45 months), the average flexion arc was 113 degrees , with mean flexion of 132 degrees and mean flexion contracture of 20 degrees . The mean Broberg-Morrey score was 90 points (range, 61-100 points). Ratings were excellent in 9 patients, good in 10, and fair in 4. Mild radiographic signs of arthrosis (type 1 Broberg-Morrey) were present in 2 patients. Slight postreduction subluxation of the elbow, without detrimental contact of the articular surfaces, a type of pseudosubluxation of the elbow sometimes referred to as the "drop sign," can be treated with active exercises and avoidance of varus stress.     

The long-term results of Swanson silicone rubber interpositional wrist arthroplasty

Fifty-three Swanson silicone rubber interpositional wrist arthroplasties were done in 42 patients. A painful rheumatoid wrist was the most common operative indication. Very acceptable clinical results were obtained early in follow-up, with more than 90% of the wrists obtaining significant pain relief. However, in the group of wrists followed for more than 2.5 years, only 61% had good or excellent results. The reoperation rate in this group was 25%. Postoperative complications included prosthetic breakage (9.4%), ulnar cap breakage (71%), and a very high incidence of progressive radiographic deterioration (70%).     

Simultaneous dislocation of the proximal and distal radioulnar joints: A case report

A 34-year-old man was struck on his left arm by a heavy piece of wood. Clinical and radiographic examinations revealed anterior dislocation of the radial head and palmar dislocation of the ulnar head. Under general anesthesia both dislocations were reduced and the arm was immobilized in a plaster cast in supination for 5 weeks. 5 months after the injury, the patient had normal motion in both the wrist and elbow and returned to his previous occupation as a wood-cutter. At reexamination 4 years later, he had no pain and no instability in his wrist or elbow.     

Mechanisms of load transfer in the cadaver forearm: role of the interosseous membrane

Forces transmitted through the distal ulna and proximal radius, relative motion between the radial head and capitellum, and measurements of tissue strain and local fiber tension within the central band of the interosseous membrane were recorded as cadaveric forearms were loaded axially through the wrist. With the elbow in valgus alignment (the radial head in direct contact with the capitellum), an average of 93% of force applied to the wrist was transferred directly through the radius to the elbow with no appreciable load transfer through the interosseous membrane. With varus alignment (initial gap between the radial head and capitellum) load applied to the wrist displaced the radius proximally an average of 1.1 mm until radial head contact occurred at a mean applied wrist force of 89.0 N. Proximal displacement of the radius generated strain in the central band of the interosseous membrane and created a more ulnar positive wrist, which in turn increased distal ulnar loading; distal ulnar force averaged 19% and interosseous membrane averaged 54% of applied wrist force. Distal ulnar loading was unaffected by 25 degrees wrist flexion-extension or by 20 degrees of radioulnar deviation. With 40 degrees ulnar deviation, mean distal ulnar forces were 18% and 48% of applied wrist force for valgus and varus elbow alignments, respectively. Mean load-sharing percentages at the wrist and elbow were not significantly different between 222. 5 N and 133.5 N of applied force for any wrist position and were unaffected by the angle of elbow flexion.     

Stability of the forearm after resection of the distal ulna and proximal radius in rheumatoid arthritis: report of 11 cases

Combined resection of radial head and distal ulna could jeopardize the stability and kinematics of the forearm bones. The goals of this retrospective study was to investigate these data after resection of distal ulna and proximal radius in rheumatoid arthritis. Between 1990 and 1998, eleven patients had these bone resections combined with implantation of elbow prostheses (eight Kudo and three GSB III). Wrist surgery consisted in five wrist arthrodeses combined with Darrach procedure, four Sauvé-Kapandji procedures and two isolated Darrach procedures. Mean age at surgery was 58 years and the average follow-up was 40 months. We assessed at follow-up: 1) wrist and elbow pain according to Gschwend; 2) stability of the forearm bones (cubitus valgus angle, impingement of the proximal radial stump with humerus, giving away accident of the ulnar distal stump); 3) wrist and elbow mobility. At follow-up six patients had no pain at the elbow and five had slight occasional pain. At the wrist, five patients had no pain and six slight occasional pain. Elbow motion was increased (from mean 83 degrees [50 degrees-100 degrees] to mean 110 degrees [85 degrees-135 degrees]) excepted in supination which slightly decreased (from mean 3 degrees [40 degrees-90 degrees] to mean 75 degrees [85 degrees-90 degrees]). Mean wrist mobility was impaired because of the five combined radiocarpal arthrodeses. If these five wrist arthrodeses were excluded, the mean ranges of motion were: 10 degrees in flexion, 16 degrees in extension, 2 degrees in radial deviation, 14 degrees in ulnar deviation. At follow-up, no patient had giving away accident of the ulnar distal stump nor impingement between radial stump and humerus in full flexion. Average cubitus valgus was 10 degrees. This study pointed out the predominant effect of the interosseous membrane in stability of the forearm bones.     

Radiologic and patient-reported functional outcomes in an elderly cohort with conservatively treated distal radius fractures

PURPOSE: There have been few prospective studies of elderly patients with conservatively treated distal radius fractures and little is known about the relationship between acceptable radiographic reduction and functional outcomes in this population. We hypothesized that acceptable fracture reduction (according to standard radiographic dorsal/volar tilt criteria) would be associated with better functional outcomes and greater satisfaction. METHODS: Seventy-four patients who were at least 50 years of age with conservatively managed distal radius fractures were recruited from 2 large urban emergency departments from January 2001 to December 2001. Patients with wrist fractures treated in the emergency department and discharged home were included; patients admitted to the hospital or who required surgical reduction were excluded. Standard lateral radiographs were taken after the final cast was removed. These were reviewed independently by a reference-standard musculoskeletal radiologist and the degree of dorsal/volar tilt was recorded. This value was dichotomized according to standard published dorsal/volar tilt criteria as acceptable (dorsal tilt <10 degrees or volar tilt <20 degrees ) or unacceptable (dorsal tilt >10 degrees or volar tilt >20 degrees ). The Medical Outcomes Study Short-Form 12 (SF-12); the Disabilities of the Arm, Shoulder, and Hand questionnaire; and a patient satisfaction survey were used to assess patient-reported outcomes 6 months after the injury. RESULTS: The average dorsal/volar tilt measured by the reference standard radiologist was 3.4 degrees (SD=13.6) dorsal; overall 47 patients (64%) were considered to have an acceptable radiographic reduction. Acceptable radiographic reduction was not associated with better generic physical or mental health status, lesser degrees of upper-extremity disability, or greater satisfaction with outcomes than was unacceptable reduction. Overall 44 of 74 patients (59%) reported being satisfied or very satisfied with their functional status at 6 months. CONCLUSIONS: Contrary to our hypotheses we found that acceptable radiographic reduction (according to dorsal/volar tilt criteria) was not associated with better self-reported functional outcomes or increased satisfaction at 6 months in elderly patients with conservatively treated distal radius fractures.     

Acceptable parameters for alignment of distal radius fracture with conservative treatment in elderly patients

BackgroundThere is a conflict in the treatment of distal radius fractures in elderly patients, because fracture reduction does not appear to be as strongly associated with functional outcomes as in younger patients. The purpose of this study was to evaluate radiographic findings of acceptable reduction without leading to wrist dysfunction and poor outcomes.MethodsFifty-two active and healthy elderly patients with conservatively managed distal radius fractures were included in the study. They consisted of 7 men and 45 women, all 60 years or older. Radiographic assessment included volar tilt, radial inclination and ulnar variance, and outcome evaluation included the Mayo wrist score and DASH score. As a control group, the preoperative radiographic and clinical outcomes were examined as well for 19 patients older than 60 with malunion, for whom corrective osteotomy was performed because of wrist dysfunction. The radiographic parameters and clinical outcomes were compared between the two groups in a statistical manner. Correlation coefficients of the radiographic parameters with Mayo wrist score and DASH score were analyzed by multiple regression.ResultsVolar tilt (mean —1.2°) and ulnar variance (mean 2.5 mm), as well as Mayo wrist score (mean 80.0 points) and DASH score (mean 8.6 points) in the objective group were significantly superior to those in the control group when comparing radiographic parameters and clinical outcomes. There was no significant difference between the two groups in regard to RI (mean 14.9°). Multiple regression analysis revealed that volar tilt and ulnar variance were significantly correlated with the clinical outcomes in the objective.ConclusionThe parameters of volar tilt and ulnar variance had a significant correlation with clinical outcomes. Clinical outcomes significantly worsened when those parameters exceeded a tolerable range. In elderly patients, it is important to determine an appropriate therapeutic modality for a distal radius fracture when considering the acceptable parameters for alignment.     

Ulnar nerve pressure: influence of arm position and relationship to somatosensory evoked potentials.

BACKGROUND: Although the ulnar nerve is the most frequent site of perioperative neuropathy, the mechanism remains undefined. The ulnar nerve appears particularly susceptible to external pressure as it courses through the superficial condylar groove at the elbow, rendering it vulnerable to direct compression and ischemia However, there is disagreement among major anesthesia textbooks regarding optimal positioning of the arm during anesthesia. METHODS: To determine which arm position (supination, neutral orientation, or pronation) minimizes external pressure applied to the ulnar nerve, we studied 50 awake, normal volunteers using a computerized pressure sensing mat. An additional group of 15 subjects was tested on an operating table with their arm in 30 degrees, 60 degrees, and 90 degrees of abduction, as well as in supination, neutral orientation, and pronation. To determine the onset of clinical paresthesia compared to the onset and severity of somatosensory evoked potential (SSEP) electrophysiologic changes, we studied a separate group of 16 male volunteers while applying intentional pressure directly to the ulnar nerve. Data are presented as mean (median; range). RESULTS: Supination minimizes direct pressure over the ulnar nerve at the elbow (2 mmHg [0; 0-23]; n = 50), compared with both neutral forearm orientation (69 mmHg [22; 0-220]; P < 0.0001), as well as pronation (95 mmHg [61; 0-220]; P < 0.0001). Neutral forearm orientation also results in significantly less pressure over the ulnar nerve compared to pronation (P < or = 0.04). The estimated contact area of the ulnar nerve with the weight-bearing surface was significantly (P < 0.0001) smaller in the supine position (2.2 cm2 [0.5; 0-9]; n = 50) compared with both neutral orientation (5.5 cm2 [5.0; 0-13]) and pronation (5.8 cm2 [6; 0-12]). With the forearm in neutral orientation, ulnar nerve pressure decreased significantly (P < or = 0.01; n = 15) as the arm was abducted at the shoulder from 0 degrees to 90 degrees. In the 16 male subjects tested, notable alterations in ulnar nerve SSEP signals (decrease > or = 20% in N9-N9' amplitude) were detected in 15 of 16 awake males during application of intentional pressure to the ulnar nerve. However, eight of these subjects did not perceive a paresthesia, even as SSEP waveform amplitudes were decreasing 23-72%. Two of these eight subjects manifested severe decreases in SSEP amplitude (> or = 60%). CONCLUSIONS: Extrapolating these results to the clinical setting, the supinated arm position is likely to minimize pressure over the ulnar nerve. With the forearm in neutral orientation, pressure over the ulnar nerve decreases as the arm is abducted between 30 degrees and 90 degrees. In addition, up to one half of male patients may fail to perceive or experience clinical symptoms of ulnar nerve compression sufficient to elicit SSEP changes.     

Symptoms and radiographic findings in the proximal and distal ulnar stumps after the Sauvé-Kapandji procedure for treatment of chronic derangement of the distal radioulnar joint

PURPOSE: We analyzed correlations between symptoms and radiographic findings with respect to the proximal and distal ulnar stumps after the Sauvé-Kapandji procedure for treating chronic derangement of the distal radioulnar joint. METHODS: A total of 26 patients were studied (13 men, 13 women) with a mean age of 46 years at examination. Clinical assessment included elicitation of postoperative symptoms related to the proximal and distal ulnar stumps. In the radiographic study the radioulnar distance in the neutral wrist position and the presence or absence of scalloping at the radius were determined from posteroanterior (PA) views. The total mobility distance of the proximal ulnar stump was measured on the PA and lateral views while the wrist moved from radial to ulnar deviation or from extension to flexion. RESULTS: Eleven patients complained of tenderness over the distal ulnar stump and 5 patients felt discomfort around the proximal ulnar stump during forearm rotation. The postoperative radioulnar distance in patients with tenderness was significantly smaller than in the group without tenderness. Scalloping at the radius was shown in 9 patients but it was not related to the radioulnar distance. The total mobility distance of the proximal ulnar stump on the PA view was significantly greater in patients with tenderness than in those without, and it also was significantly greater in patients with scalloping than in those without. The total mobility distance on the lateral view was significantly greater in the group with discomfort than in the group without discomfort. CONCLUSIONS: The radioulnar distance was related to tenderness over the distal ulnar stump but not to the scalloping. Tenderness and scalloping each were related to radioulnar instability of the proximal ulnar stump. Discomfort around the proximal ulnar stump was related to dorsovolar instability of the stump. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic, Level IV.     

Unreconstructible radial head fracture: resection, implant of Swanson or prosthesis? Retrospective comparative study

Treatment of unreconstructible comminuted fractures of the radial head remains a therapeutic challenge. Thirty two patients sustained unreconstructible radial head fracture between 1969 and 1999 and have been treated by resection (16 patients), by Swanson implant (8 patients), or by Judet prosthesis (8 patients). The three groups of patients were reviewed clinically and radiologically by two surgeons not involved in their treatment. Functional outcomes of the elbow (Morrey scoring-SOO scoring system, instability, cubitus valgus) and involvement of the wrist (pain, grasp, RUD instability) were evaluated with a mean follow up of 15 years (6-27.7). Elbow or wrist arthritis, ulnar variance, and evolution of Swanson implants were evaluated on standard radiographs. The Judet prosthesis group was evaluated with DASH scoring. Half of the patients were male and 1/3 had a work-related injury. Regarding the following criteria, there was no significant difference between the resection and the Swanson group: Morrey scoring 77/100, SOO scoring 7.4/11, mean flexion was 130 degrees, mean deficient extension was 18 degrees, mean pronation 60 degrees, mean supination 67 degrees, grasp reached 90% of the controlateral side. Arthritis was noted with the same frequency at the elbow (87%), and wrist levels (66%) in each group. Ninety four percent (94%) of patients in the resection group and 89% in the Swanson group were satisfied. Excellent and good results were reported more frequently in the Swanson group (37% resection group, 51% Swanson group). In the resection group the following complications were significantly more frequent: ulnar nerve irritation (2 x), ulnar head dislocation (2 x), ulnar head instability (3 x), para articular ossification (5 x), ulnar variance positive in all cases (mean value 3.20 mm). In the Swanson group only two implants were found to be destroyed at follow-up. In the prosthesis group function and satisfaction were higher than the two other groups but with a shorter follow up. Excellent and good results were reported in 62.5% cases with a DASH scoring between 0 and 16.7. Comminuted fractures of the radial head treated by resection or Swanson implant are both followed by fair results (same functional scoring). Only the level of complications differs between groups: at elbow level for Swanson group, at wrist level for the resection group. Patients in the Swanson group were most frequently satisfied. Metal radial head implant is an attractive solution yielding good functional outcomes in recent reported limited series and in our personal experience, but with a very short follow-up.     

Medial approach for fixation of displaced supracondylar fractures of the humerus in children

This study aimed at evaluating our protocol for displaced Gartland Type 3 supracondylar fractures of the humerus in children. Forty-eight children had 49 fractures during the study period, from 1997 to 2002; they were included in the study. Their mean age was 7.02 years. They all were treated with crossed K-wires. The medial wire was always put under direct vision through a medial approach. All fractures were manipulated maximum twice. Ten patients (23.25%) required open reduction which was done through the same medial approach which we use for medial pin placement. No patient had iatrogenic ulnar nerve neuropathy. At final review radiographs were taken of the normal and operated sides and films were compared with immediate post-op films. The postoperative mean value of Bauman's angle in the affected elbow was 76.7 degrees with a range of +/- 1.0 degrees and 74.8 degrees with a range of +/- 0.6 degrees on the unaffected elbow. Carrying angle and movements of operated and normal sides were measured at review. According to Flynn's criteria, all patients showed satisfactory results. We conclude that cross K-wiring gives excellent results; the medial approach provides an excellent view of the supracondylar area, leaves a cosmetically acceptable scar and enables to avoid iatrogenic injury to the ulnar nerve.     

Augmentation of distal radius fracture fixation with coralline hydroxyapatite bone graft substitute.

We implanted coralline hydroxyapatite bone graft as a substitute for autogenous bone graft to support the reduced articular surface of 21 consecutive patients with distal radius fractures treated with external fixation and K-wires. The purpose of this single-cohort retrospective study was to report the outcomes of treatment with this material, complications associated with its use, and its efficacy in supporting the articular surface reduction. Eighteen patients were available for independent evaluation of motion, subjective outcome analysis, and final radiographic analysis at an average of 35 months after surgery. Wrist motion averaged 90% of the uninjured wrist and grip strength measured 75% of the uninjured side. Results in 17 of the 18 cases were rated as good or excellent by the criteria of Gartland and Werley; 12 by the criteria of Green and O'Brien. Seventeen had good or excellent radiographic results by the modified Lidstrom radiographic scoring system. The average DASH functional/symptom score was 90.3 (maximum, 100). Radiographic parameters were restored to an average of 12 mm radial length, 4 degrees volar tilt, 23 degrees radial inclination, and 0.6 mm positive ulnar variance. Articular reduction was maintained in all patients. A complication related to the use of coral was a 0.5 mm prominence of coralline hydroxyapatite beyond the subchondral line at the radiocarpal joint in 1 patient, which was not present on final radiographs. Coralline hydroxyapatite was effective at maintaining articular surface reduction when used in combination with external fixation and K-wires and had a safety profile comparable to other forms of treatment.     

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.