Inter- and intraobserver variability of radiographic measurements of knee alignment.

To evaluate the variability of radiographic measurement of knee alignment by different observers, as well as repeated measurements by the same observer, standing anteroposterior radiographs of both knees of 36 patients presenting with knee pain were analyzed. Four physicians independently measured the anatomic tibiofemoral angle of both knees for a total of 72 measurements for each observer. These measurements were then repeated 1 month later in a random and blinded fashion. The same handheld goniometer was used for all measurements. The second measurement was within 3.1 degrees of the first measurement 95% of the time, and within 4 degrees 98% of the time. The maximum difference was 6 degrees. Among all four observers, measurements were within 3.7 degrees of each other 95% of the time with a maximum difference of 6 degrees. In addition to radiographic measurement, one physician also performed clinical measurement of knee alignment on these 36 patients using the same handheld goniometer. The clinical measurement was within 5 degrees of the same clinician's radiographic measurement 95% of the time with a maximum difference of 7 degrees. This variability in measuring radiographic alignment should be considered when making decisions on the need for surgical intervention or when evaluating results of procedures that relate to coronal plane alignment of the knee.

Biomechanical evaluation of the origin of the long head of the biceps tendon.

PURPOSE: Lesions of the superior glenoid labrum extending anterior and posterior (SLAP) have recently been recognized as important sources of shoulder pain and dysfunction. Among the 4 described types of SLAP lesions, the type II SLAP involves detachment of the superior labrum from the bony glenoid and destabilization of the origin of the long head of the biceps tendon (LHBT). The purpose of this cadaveric biomechanical study was to evaluate the relative contribution regarding linear stiffness and displacement under load of the 2 origins of the LHBT: the superior glenoid labrum and the supraglenoid tubercle (the biceps anchor). TYPE OF STUDY: Cadaveric biomechanical study. METHODS: Seven pairs of fresh-frozen cadaveric shoulders were dissected free of all soft tissue except for the glenoid labrum and LHBT. Tension from 0 to 55 N was applied to the LHBT while keeping the tendon perpendicular to the face of the glenoid. Each specimen was tested for linear stiffness and biceps tendon displacement in the intact state, after releasing 1 of the LHBT origins, and after releasing the remaining origin. RESULTS: The average stiffness of the LHBT origin was 103 N/mm. Sectioning the anchor alone resulted in a 52% reduction in linear stiffness, whereas only detaching the superior glenoid labrum from the 10 o'clock to the 2 o'clock position resulted in a 15% reduction in linear stiffness. Maximum displacement of the biceps tendon origin in the intact state at the 55 N load averaged 0.99 mm. With a minimum load applied, displacement changed less than 1 mm unless both origins were released. CONCLUSIONS: The results indicate that the biceps anchor is the primary restraint of the LHBT and that the superior labrum is a secondary restraint in regard to linear stiffness. However, disruption of both restraints is required to produce the laxity typically seen in a type II SLAP lesion.

Reliability of the Lichtman classification of Kienböck's disease.

The purpose of this study was to establish the interobserver reliability and intraobserver reproducibility of the staging of Kienböck's disease according to Lichtman's classification. Posteroanterior and lateral wrist radiographs of 64 patients with a diagnosis of Kienböck's disease and 10 control subjects were reviewed independently by 4 observers on 2 separate occasions. The reviewers included 3 hand fellowship-trained surgeons and 1 orthopedist who was not fellowship-trained in hand surgery. A stage was assigned to each set of radiographs according to the Lichtman classification. Paired comparisons for reliability among the 4 observers showed an average absolute percentage agreement of 74% and an average paired weighted kappa coefficient of 0.71. Furthermore, all the controls were correctly classified as stage I, which is in accordance with the Lichtman system. With regard to reproducibility, observers duplicated their initial readings 79% of the time with an average weighted kappa coefficient of 0.77. These results indicate substantial reliability and reproducibility of the Lichtman classification for Kienböck's disease.

Cyclic pull-out strength of hamstring tendon graft fixation with soft tissue interference screws. Influence of screw length.

Blunt-threaded interference screws used for fixation of hamstring tendons in anterior cruciate ligament reconstructions provide aperture fixation and may provide a biomechanically more stable graft than a graft fixed further from the articular surface. It is unknown if soft tissue fixation strength using interference screws is affected by screw length. We compared the cyclic and time-zero pull-out forces of 7 x 25 mm and 7 x 40 mm blunt-threaded metal interference screws for hamstring graft tibial fixation in eight paired human cadaveric specimens. A four-stranded autologous hamstring tendon graft was secured by a blunt-threaded interference screw into a proximal tibial tunnel with a diameter corresponding to the graft width. Eight grafts were secured with a 25-mm length screw while the other eight paired grafts were secured with a 40-mm length screw. During cyclic testing, slippage of the graft occurred as the force of pull became greater with each cycle until the graft-screw complex ultimately failed. All grafts failed at the fixation site, with the tendon being pulled past the screw. There were no measurable differences in the mean cyclic failure strength, pull-out strength, or stiffness between the two sizes of screws. Although use of the longer screw would make removal technically easier should revision surgery be necessary, it did not provide stronger fixation strength than the shorter, standard screw as had been postulated.

Irreducible anterior shoulder dislocation with fracture of the greater tuberosity.

The combination of an anterior shoulder dislocation and an avulsion fracture of the greater tuberosity can usually be reduced by closed methods. This report describes a patient requiring open reduction and division of the subscapularis tendon before reduction of the glenohumeral dislocation could be achieved.

Post-traumatic heterotopic ossification about the elbow.

To evaluate the effect of surgical timing on the formation of heterotopic ossification about the elbow, 71 consecutive patients with elbow trauma requiring operative management were evaluated. Fourteen patients were excluded because they suffered from head injury, burns, or severe open injuries requiring surgery on two or more occasions. Sixteen patients were lost to follow-up, leaving a group of 41 patients. The average age of patients was 35 years. The fractures involved the olecranon in 19, distal humerus in 12, and radial head/neck in 10 patients. Six of these fractures were accompanied by a dislocation. Eleven were open injuries; the remaining 30 were closed. Bone grafting was performed in nine patients. The interval between injury and surgical intervention averaged 57 hours. None (0%) of 17 patients treated within 48 hours developed grade II, III, or IV heterotopic ossification, whereas 8 (33%) of 24 patients treated after 48 hours developed grade II, III, or IV heterotopic ossification. There were no significant differences in demographic or injury parameters between these two groups. These findings suggest that fixation of unstable elbow fractures within 48 hours of injury may reduce the formation of ectopic bone.

Lower extremity morphology and alignment and risk of overuse injury.

OBJECTIVE: Lower extremity alignment factors, including tibiofemoral angle, quadriceps angle (Q-angle), and limb length discrepancies, are commonly thought to be clinically relevant as contributing factors to overuse injuries of the lower extremities. To explore the scientific rationale for these clinical beliefs, we conducted a review of the available English language literature from 1966 to July 1997 relating overuse injury to lower extremity alignment. DATA SOURCES: MEDLINE was searched for medical subject headings and title key words to locate published works relating lower extremity morphologic characteristics to risk of overuse injury. Additional references were reviewed from reprint collections and reference lists of published work. DATA EXTRACTION AND SYNTHESIS: Relevant studies were reviewed for strengths and weaknesses in design, analysis, and conclusions. Synthesis across studies concentrated on commonalities and differences of methods in definition of exposure and outcome variables. MAIN RESULTS: Six population-based studies have been conducted evaluating some aspect of lower extremity alignment as a risk factor for overuse injury. Three of these studies evaluated military recruits in basic training, two studied mixed groups of athletes and one studied folk dancers. The time frame across studies ranged from 12 weeks to 52 weeks. A key finding was the considerable variation in the measure of lower limb alignment used as the exposure variable, as well as the method of measurement used to quantify the exposure. Some studies relied on visual examination, whereas others used digitized photographic techniques. Moreover, each study varied in the definition used for overuse injury; outcomes ranged from self-reported cases of shin splints to radiographic confirmation of stress fracture. Five of the six studies evaluated some aspect of foot morphology, whereas only one evaluated full leg alignment parameters. CONCLUSIONS: Results were conflicting but, in general, did not support clinical beliefs of the detrimental effects of decreased longitudinal foot arch and varus tibiofemoral alignment as risk factors for lower extremity overuse injury. Differences in methodologic rigor and outcome definition prevent a meaningful synthesis of existing work. Directions for future research are suggested.

Untreated osteochondritis dissecans of the femoral condyles: prediction of patient outcome using radiographic and MR findings.

OBJECTIVE: We investigated the usefulness of plain film and MR findings in predicting the outcome of conservatively treated patients with femoral osteochondritis dissecans. DESIGN: Without knowledge of the clinical outcome, we retrospectively reviewed the initial plain films and MR examinations. Each MR examination was evaluated for the four MR findings of instability. PATIENTS: Fourteen patients were studied in whom osteochondritis dissecans of a femoral condyle had been treated conservatively for periods ranging from 1.2 to 8.5 years. RESULTS AND CONCLUSION: Three of five patients with an open femoral growth plate and one of nine patients with a closed growth plate had a good clinical outcome. Both patients with lesions smaller than 160 mm2 in area had a good outcome and ten of 12 patients with larger lesions had a poor outcome. Both patients with stable lesions by MR imaging had a good outcome while ten of 12 patients with a lesion unstable by MR imaging had poor outcomes. All six patients with a cartilage fracture or articular defect had poor outcomes. The results of this study should be considered preliminary since only 14 patients were followed. However, it appears that a good clinical outcome is likely when the femoral growth plate is open, when the osteochondritis dissecans is small, and when the lesion is stable by MR imaging. When a cartilage fracture or articular defect is found on MR imaging, the patient is likely to have a poor outcome.

Stoma creation through the stoma site: a rapid, safe technique.

UNLABELLED: Stoma creation often involves a separate laparotomy incision. Recently, laparoscopy was suggested to minimize the morbidity associated with conventional open stomal techniques. We describe and evaluate a technique of stoma creation done directly through the stoma site, avoiding both laparotomy and laparoscopy. METHODS: Charts of 36 patients who underwent attempted stoma creation using this closed technique were retrospectively reviewed. RESULTS: A total of 32 patients had stomas successfully created in this fashion (closed group); although four patients failed and required laparotomy (open group), there was an overall success rate of 89 percent. Blood loss (17 +/- 5 vs. 350 +/- 130 ml; P < .001), operative time (52 +/- 8 vs. 169 +/- 35 minutes; P < 0.001), and complications (3/32 vs. 4/4; P < 0.001) favored the closed group. No factors, including diagnosis, obesity, or previous abdominal surgery were identified that contraindicated use of the closed technique. CONCLUSIONS: Stomas can be safely made in a high proportion of patients without the need for laparotomy or laparoscopy. Failure of the closed technique identifies a group of patients who have a high associated operative time, blood loss, and morbidity when laparotomy is used for stoma creation and in whom laparoscopic procedures may improve results.

Reassessment of the MR criteria for stability of osteochondritis dissecans in the knee and ankle.

OBJECTIVE: T2-weighted MR images has been reported to be an accurate method for assessing osteochondritis dissecans. We reviewed our MR experience to confirm the accuracy of the published criteria of instability. We also assessed the value of each of four MR signs of instability. DESIGN: We reviewed the original MR interpretations, arthroscopic reports, and MR examinations of 40 patients with osteochondritis dissecans of the talar dome or femoral condyles. Arthroscopy was used as the gold standard for stability. The MR examinations were reviewed retrospectively for a high-signal-intensity line or cystic area beneath the lesion, a high-signal-intensity line through the articular cartilage, or a focal articular defect. PATIENTS: All patients who had undergone MR imaging for osteochondritis dissecans from 1990 to 1993 were reviewed. Forty patients were identified who had arthroscopy after the MR examination. There were 30 male and 10 female patients with an average age of 25.7 years. Thirty-one lesions were in femoral condyle and nine were in the talar dome. RESULTS AND CONCLUSIONS: The original MR interpretations correctly identified 35 of the 36 unstable lesions and all 4 stable lesions, giving a sensitivity of 0.97 and specificity of 1.0. There was a 98% agreement between the original and retrospective diagnoses. A high-signal-intensity line was seen beneath 72% of the 36 unstable lesions. The other three signs were noted in 22-31% of the unstable lesions. Fifty-six percent of the unstable lesions showed only one sign of instability. MR imaging is a highly sensitive method for detection of unstable osteochondritis dissecans. The presence of any one sign indicates instability, the most frequent sign being an underlying high-signal-intensity line. Because we examined only four stable lesions, our 95% confidence interval of 0.40-1.0 for a specificity of 1.0 gives only a limited estimate of the specificity of MR.

Awake epidural anesthesia is associated with improved natural killer cell cytotoxicity and a reduced stress response.

BACKGROUND: Laparotomy under general anesthesia is associated with depressed natural killer cell cytotoxicity (NKCC) and compromised clearance of tumor cells. We tested the hypothesis that awake epidural anesthesia (AEA) improves NKCC compared to conventional general endotracheal anesthesia (GEA). PATIENTS AND METHODS: Preoperative, perioperative, and postoperative (day 3) NKCC, plasma epinephrine, norepinephrine, cortisol levels, and 24-hour urinary cortisol levels were measured in 20 patients undergoing open colectomy under either AEA or GEA. RESULTS: Preoperative and postoperative measurements were not significantly different in the two groups. Patients receiving GEA had a significant reduction in NKCC from 36% +/- 4% preoperatively to 22% +/- 4% perioperatively (P = 0.02). Patients receiving AEA had no significant change in NKCC. Perioperative plasma epinephrine and cortisol levels were higher with GEA than AEA. The perioperative 24-hour urinary cortisol excretion values were significantly higher in the group receiving GEA, suggesting a greater stress hormone response in this group compared to AEA patients. CONCLUSIONS: Compared to GEA, AEA appears to preserve perioperative NKCC. This effect may be related to an attenuated stress hormone response associated with AEA. Cancer patients may have improved killing of embolized tumor cells during surgery performed under AEA.

Continuous epidural analgesia using fentanyl and bupivacaine after total knee arthroplasty.

Eighty consecutive patients undergoing unilateral total knee arthroplasty received postoperative analgesia consisting of a continuous epidural infusion of fentanyl and bupivacaine. Nineteen patients (24%) were unable to complete the three-day course of epidural infusion: two thirds for technical reasons and one third because of adverse effects. The remaining 61 patients (76%) successfully completed the 72-hour protocol. The benefits in this group included a shorter hospital stay (8.3 versus 9.5 days, p < 0.01) and earlier return of flexion (p < 0.05) as compared with the group that had the epidural catheter removed prematurely. When compared with previous experiences with continuous epidural analgesia using Duramorph and bupivacaine for the first three days after TKA in 56 patients, the current group of 80 patients had shorter average hospitalization (8.6 versus 9.7 days, p < 0.01) and earlier return of flexion (p < 0.001). Patient acceptance was excellent with either agent. Confusion and pruritus were significantly less common with fentanyl, but the incidence of hypotension was increased. Nausea was problematic in both groups. The incidence of respiratory depression was 5% for either opiate. The degree of hypoventilation and treatment required for it were less severe with fentanyl, however.