Ultrasonic measurement of the anterior translation in the shoulder joint

A new method for measuring the anterior translation in the shoulder joint by dynamic ultrasound was evaluated. We placed a 3.5-MHz transducer on the shoulder anteriorly. By using 3 bony landmarks, we then measured the anterior translation of the humeral head with a force of 90 N applied posteriorly. We performed such measurements in 20 subjects with healthy shoulders and in 20 patients with unilateral shoulder instability. There was a mean translation of 1.9 mm in healthy shoulders and 4.9 mm in unstable shoulders (P < .01). The mean difference between the 2 sides in subjects with normal shoulders was 0.7 mm, whereas the mean difference in patients with instability was 2.8 mm (P < .01). The normal shoulders were examined by 2 examiners to determine the degree to which different examiners' measurements might vary. Although one examiner recorded higher values than the other, the new method seems suitable for measuring increased laxity in unstable shoulders.     

Glenohumeral translation after total shoulder arthroplasty

To define the amount and direction of anteroposterior translation of the glenohumeral joint after total shoulder arthroplasty, 13 patients who had previously undergone nonconstrained total shoulder arthroplasty were studied roentgenographically. Patients were placed on the x-ray table in a supine position, and axillary roentgenograms of the shoulder were made with the arm at 90° abduction and in four positions within the horizontal plane of motion: - 30° (horizontal extension), 0° (neutral), 30°, and 60° (horizontal flexion). For all positions the shoulder was in neutral rotation. The center of the prosthetic humeral head was identified, and the distance between it and a perpendicular line bisecting the glenoid component was measured. At follow-up the patients had statistically significant improvements in pain, motion, and function. No patients had any clinical evidence of instability. The mean total translation was 4 mm posteriorly (range 0 to 12 mm). Most translation occurred between - 30° and 30°. Anteroposterior translation appears to occur in a posterior direction. For this to occur the prosthetic humeral head slides onto the polyethylene rim of the glenoid component, subjecting it to eccentric loading and the possibilities of wear, polyethylene debris formation, induction of osteolysis, and subsequent component loosening.     

Intraoperative decision making in the treatment of shoulder instability

Between April 1990 and April 1994, 100 patients with a preoperative diagnosis of anterior instability underwent a diagnostic arthroscopy of the shoulder. Patients with isolated SLAP lesions were excluded from the study. Patients with multidirectional instability, bony Bankart lesions, and large Hill-Sachs lesions were also excluded. Football players and dominant arm throwing athletes were also excluded. Thirty patients remained who had post-traumatic, unidirectional, anterior instability and a repairable Bankart lesion and did not have any exclusions as noted above. All of these patients underwent an initial attempt at an arthroscopic Sure-Tac stabilization (Smith & Nephew, Andover, MA). Twenty-three patients met our criteria for a secure fixation but 7 did not. These 7 underwent an immediate arthrotomy and open Bankart repair. All of the patients were available at follow-up at an average of 47 months (range, 36 to 72 months). The patients were evaluated by the Rowe shoulder rating scale. There have been two cases of recurrent subluxation and one case of recurrent dislocation in the Sure-Tac group. All three occurred over 2 years later. All three had recurrent Bankart lesions and underwent an arthrotomy and Bankart repair. There were no cases of recurrence of subluxation or dislocation in our initial open Bankart repair group. Sure-Tac arthroscopic anterior stabilization of the shoulder can initially give good results but these results appear to deteriorate over time and increased activity of the patient. We currently do not recommend a Sure-Tac repair even in a selective group of patients with an isolated Bankart lesion. This is based on our excellent results following an open Bankart repair and a 13% recurrence rate following Sure-Tac stabilization in carefully selected patients.Arthroscopy 1998 May-Jun;14(4):389-94     

术中测量股骨假体肩部与大转子顶点垂直高度预防全髋关节置换术后下肢不等长

目的探讨全髋关节置换术中股骨假体肩部与大转子顶点垂直高度（顶肩距）与术后下肢等长的关系。方法单侧初次生物型全髋关节置换术患者41例进行前瞻性研究。术前临床检查及X线仔细测量评估〉术中采用腿与腿比较、Shuck试验、稳定试验等判断肢体长度。同时测量股骨假体肩部与大转子顶点垂直距离来均衡双下肢长度。结果符合纳入标准的患者41例,术后X线测量双下肢不等长（双下肢长度差异大于lOmm）的发生率为21．95％（9／41）,术后患肢相对于健肢的长度与术中测量股骨假体肩部至大转子顶点垂直高度成负相关。结论术中采用多种方法综合评估肢体长度可有效降低术后肢体不等长的发生率．通过术中测量顶肩距来指导选择合适型号和颈长的假体可作为控制术后下肢等长的有效方法之一。     

The reproducibility of measurement of shoulder movement

To study the reproducibility of the measurement of shoulder movement, we have examined a series of 64 patients with and without shoulder problems, measuring active elevation, abduction, and external rotation in adduction using an inclinometer. The difference within which readings by different observers were expected to lie for 95% of the pairs of observations ranged from 24° to 33° for different movements in asymptomatic shoulders and from 24° to 41° in those with unilateral shoulder symptoms awaiting surgery.     

The reproducibility of measurement of shoulder movement

To study the reproducibility of the measurement of shoulder movement, we have examined a series of 64 patients with and without shoulder problems, measuring active elevation, abduction, and external rotation in adduction using an inclinometer. The difference within which readings by different observers were expected to lie for 95% of the pairs of observations ranged from 24° to 33° for different movements in asymptomatic shoulders and from 24° to 41° in those with unilateral shoulder symptoms awaiting surgery.     

The reproducibility of measurement of shoulder movement

To study the reproducibility of the measurement of shoulder movement, we have examined a series of 64 patients with and without shoulder problems, measuring active elevation, abduction, and external rotation in adduction using an inclinometer. The difference within which readings by different observers were expected to lie for 95% of the pairs of observations ranged from 24 degrees to 33 degrees for different movements in asymptomatic shoulders and from 24 degrees to 41 degrees in those with unilateral shoulder symptoms awaiting surgery.     

Intraoperative measurement of lower esophageal spincter pressure.

The lower esophageal sphincter pressure has been measured intraoperatively in 200 patients with gastroesophageal reflux and in three patients with achalasia. Lower esophageal sphincter pressure is measured before and during repair. Calibrating the cardia during performance of the median arcuate posterior gastropexy allows a sphincter pressure between 50 and 57 mm. Hg to be obtained at operation. The postoperative pressures have ranged between 15 and 25 mm. Hg, or approximately half of the intraoperative pressure. No patient with a spincter pressure of 15 mm. Hg or greater has reflux according to postoperative pH and pressure studies. Correction of reflux correlates well with relief of symptoms. Three patients with achalasia had intraoperative manometrics during myotomy. The lower esophageal sphincter pressure was lowered and the length of the lower esophageal sphincter was shortened. Dysphagia was corrected without producing reflux. This is the first report of measurement of lower esophageal sphincter pressure in anesthetized patients. Intraoperative measurement of sphincter pressure is a safe, simple, and reliable technique which allows the surgeon, for the first time, to determine the status of the lower esophageal sphincter during the operation. This technique should be standard for all operations on the gastroesophageal junction.     

Intraoperative CT navigation for glenoid component fixation in reverse shoulder arthroplasty

CT navigation has been shown to improve component positioning in total shoulder arthroplasty. The technique can be useful in achieving strong initial fixation of the metal backed glenoid in reverse shoulder arthroplasty. We report a 61 years male patient who underwent reverse shoulder arthroplasty for rotator cuff arthropathy. CT navigation was used intraoperatively to identify best possible glenoid bone and to maximize the depth of the fixation screws that anchor the metaglene portion of the metal backed glenoid component. Satisfactory positioning of screws and component was achieved without any perforation or iatrogenic fracture in the scapula. CT navigation can help in maximizing the purchase of the fixation screws that dictate the initial stability of the glenoid component in reverse shoulder arthroplasty. The technique can be extended to improve glenoid component position [version and tilt] with the availability of appropriate software.     

Humeral head translation during glenohumeral abduction following computer-assisted shoulder hemiarthroplasty

This study compared the effect of a computer-assisted and a traditional surgical technique on the kinematics of the glenohumeral joint during passive abduction after hemiarthroplasty of the shoulder for the treatment of fractures. We used seven pairs of fresh-frozen cadaver shoulders to create simulated four-part fractures of the proximal humerus, which were then reconstructed with hemiarthroplasty and reattachment of the tuberosities. The specimens were randomised, so that one from each pair was repaired using the computer-assisted technique, whereas a traditional hemiarthroplasty without navigation was performed in the contralateral shoulder. Kinematic data were obtained using an electromagnetic tracking device. The traditional technique resulted in posterior and inferior translation of the humeral head. No statistical differences were observed before or after computer-assisted surgery. Although it requires further improvement, the computer-assisted approach appears to allow glenohumeral kinematics to more closely replicate those of the native joint, potentially improving the function of the shoulder and extending the longevity of the prosthesis.     

Intraoperative measurement of force-length relationship of human forearm muscle

The specific relationship between force and length is one of the most important characteristics of vertebrate muscle. The only accurate method to measure the force-length characteristics is to generate a set of isometric force-time plots at different muscle lengths. In humans, such force-length characteristics mostly are based on indirect measurements that have their limitations. A method of direct, in vivo measurement of force-length characteristics of the human flexor carpi ulnaris muscle using relatively simple equipment during transposition surgery is presented. The method is proven reproducible, with an overall estimated error of 2.8%.     

Intraoperative limb length measurement in total hip arthroplasty

 In order to evaluate the efficacy of intraoperative measurement of limb length inequality (LLI), we performed a prospective study on 64 patients who underwent unilateral total hip arthroplasty. The patients were divided into 2 groups. In Group I, the LLI was evaluated by the Shuck test, and in Group II by intraoperative measurement using a Steinman pin and an adjustable caliper. Preoperative LLIs assessed on radiographs averaged 1.18 cm in Group I and 0.37 cm in Group II.

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Résumé  Pour évaluer l’efficacité de la mesure intra-opératoire de l’inégalité de la longueur d’un membre (ILM), nous avons effectué une étude prospective sur 42 patients qui ont subi une arthroplastie totale de la hanche unilatérale. Les patients furent divisés en 2 groupes selon la méthode particulière d’estimation intra-opératoire de ILM. ILM fut évalué par un essai de réduction dans le Groupe I et par une mesure intra-opératoire en utilisant une broche de Steinmann et un compas de calibrage ajustable dans le Groupe II. Sur les radiographies ILM intra-opératoires du Groupe I, la moyenne établie fut de 0,34 cm et pour le Groupe II de 0,41 cm. La moyenne établie de 1,15 cm dans le Groupe I et de 0,4 cm sur des radiographies ILM postopératoires a montré une différence significative entre les deux groupes.

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Accepted: 22 July 1998     

Intraoperative parathormone level measurement in the management of hyperparathyroidism

To investigate the potential use of intraoperative intact parathormone measurements to predict curative parathyroidectomy, we measured ionized calcium (Cai) levels and parathormone levels in 33 patients with hyperparathyroidism who underwent exploratory bilateral neck surgery. Nineteen patients each had a solitary adenoma, 13 patients had hyperplasia, and one patient had four normal parathyroid glands. These results were compared to the results for 37 patients who underwent either thyroid lobectomy (TL) (n = 10) or near-total thyroidectomy (NTT) (n = 27) and of 14 control patients who underwent miscellaneous operations. Parathormone decline after curative parathyroidectomy was 86.4 +/- 1.2% (mean +/- SE), which was significantly greater than a decline of 25.7% +/- 9.8% in three patients with persistent postoperative hyperparathyroidism (p less than 0.01). Declines were 38.5% +/- 8.7% after TL (p less than 0.01), 52.2% +/- 5.9% after NTT (p less than 0.01), and 8.3% +/- 4.3% (p less than 0.01), in the control patients. An intraoperative Cai decline of 4.0% +/- 0.6% after curative parathyroidectomy did not differ significantly from the results after TL, NTT, or miscellaneous operations in the control patients. Patients with persistent postoperative hyperparathyroidism had the greatest decline in Cai levels (7.1% +/- 2.3%; p less than 0.05). From these data we conclude that (1) a decline in parathormone level of 70% or more 20 minutes after parathyroidectomy is predictive of cure, (2) thyroidectomy, even unilaterally, produces a significant decline in parathormone level that affects interpretation of intraoperative parathormone level changes, (3) Cai level because of its slow decline is not useful in predicting effective parathyroidectomy, and (4) measurement of intraoperative parathormone level changes should not be used as a substitute for exploratory bilateral neck surgery.     

Intraoperative measurement of javid shunt flow with transit-time ultrasound

Transit-time ultrasound methods were used to measure blood flow in 37 patients undergoing carotid endarterectomy. Internal carotid flow before (ICF^bef) and after (ICF^aft) endarterectomy was measured with a 6 mm perivascular probe, and Javid shunt flow (SF) was measured with a clamp-on probe. For the entire group ICF^bef averaged 117±67 ml/min and ICF^aft was 173±67 ml/min. Shunt flow averaged 123±51 ml/min. The differences between ICF^bet and ICF^aft and between SF and ICF^aft were significant (ANOVA,p<0.01) but the difference between ICF^bef and SF was not. The relationship between ICF^bef and SF appeared to define two groups of patients. Those in whom SF was greater than ICF^bef (SF > ICF^bef) had more stenosis evident on preoperative arteriograms (64.7%±14.55% maximum single diameter stenosis) and a greater average increase in ICF (151%±159%) than those with SF ICF^bef (43.3%±20.9% stenosis and 34%±54% increase in ICF), suggesting that the relationship between SF and ICF^bef defines groups with different hemodynamic responses. The similarity between SF and ICF^bef indicates that Javid shunt flow offers adequate protection from cerebral ischemia. A practical benefit of the shunt clamp-on flow probe is the ability afforded to recognize shunt occlusions.Presented at the Twelfth Annual Meeting of the Southern California Vascular Surgical Society, Coronado, Calif., September 17–19, 1993.