Thomas W. Wright

Prosthetic usage in major upper extremity amputations.

Patterns of use of contemporary prostheses by 135 patients with major upper extremity amputations were evaluated by questionnaire. Eighty-four percent of the patients were male and 16% were female. Amputation levels represented were below elbow, 44%; above elbow, 40%; and shoulder disarticulations or forequarter amputations, 16%. The follow-up interval averaged 12 years (range, 1-67 years). One hundred and thirteen patients were fitted with either a myoelectric or body-powered prosthesis. The overall rejection rate was 38%. Thirty-nine of 42 in the below-elbow amputation group used the prosthesis and appeared to benefit the most. Eight of 141 in the wrist disarticulation group used the prosthesis: as did 9 of 21 in the above-elbow amputation group. In contrast, all bilateral amputees used their prostheses. Stiff shoulders and brachial plexus injury were both predictors for poor prosthetic usage.

Excursion and strain of the median nerve.

Five fresh-frozen transthoracic cadaver specimens (ten upper extremities) were dissected in order to measure excursion and strain of the median nerve at the wrist and the elbow in association with different positions of the shoulder, elbow, wrist, and fingers. The relationships between motions of the joints and excursion and strain at the wrist and the elbow as well as between excursion and strain were also determined. When the wrist was moved from 60 degrees of extension to 65 degrees of flexion, the median nerve at the wrist underwent a mean total excursion of 19.6 millimeters (9.2 ± 1.38 millimeters [mean and standard deviation] in extension and 10.4 ± 1.50 millimeters in flexion). The change in strain was not measurable secondary to nerve-wrinkling. Motion of the fingers from hyperextension to full flexion caused a mean total excursion of 9.7 millimeters (6.3 ± 1.31 millimeters in hyperextension and 3.4 ± 1.04 millimeters in flexion) and a change in strain of 19.0 per cent. This change in strain became more pronounced when the wrist and the fingers moved in synergy. Such strain, if constant, has been shown to decrease microvascular perfusion and nerve conduction in rabbits. With motion of the shoulder, the mean total excursion of the median nerve at the elbow was 9.1 millimeters (4.4 ± 1.64 millimeters in abduction and 4.7 ± 1.81 millimeters in adduction) and the change in strain was 13.3 per cent. With motion of the elbow, the mean total excursion was 12.3 millimeters (12.3 ± 4.20 millimeters in flexion and zero millimeters in the resting position) and the change in strain was not measurable because of the wrinkle effect in flexion. With motion of the wrist, the mean total excursion was 5.6 millimeters (4.3 ± 1.95 millimeters in extension and 1.25 ± 0.81 millimeters in flexion) and the change in strain was 14.8 per cent. With motion of the fingers, the mean total excursion was 3.4 millimeters (2.6 ± 1.13 millimeters in hyperextension and 0.80 ± 0.92 millimeter in flexion) and the change in strain was 10.3 per cent. Motion of the wrist and the fingers induced profound excursion of the median nerve at the wrist, whereas motion of the shoulder and the elbow induced marked excursion of the median nerve at the elbow. These excursions were much more pronounced when a number of joints were moved in a composite manner. Any factor that might limit normal excursion, such as scarring, could induce strains that could adversely affect the function of the median nerve. The finding that the position and movement of the limb had a profound effect on excursion and strain of the median nerve at the wrist and the elbow may aid in the understanding of the pathophysiology of median-nerve neuropathy.

Ambulatory continuous interscalene nerve blocks decrease the time to discharge readiness after total shoulder arthroplasty: a randomized, triple-masked, placebo-controlled study.

Background:A continuous interscalene nerve block (CISB) may be used to provide analgesia after shoulder arthroplasty. Therefore, inpatient stays may be shortened if CISB (1) provides adequate analgesia without intravenous opioids and (2) improves shoulder mobilization. This study investigated the relationship between ambulatory CISB and the time to reach three discharge criteria after shoulder arthroplasty. Methods:Preoperatively, patients received a CISB. All patients received a perineural 0.2% ropivacaine infusion from surgery until 06:00 the following morning, at which time they were randomly assigned either to continue perineural ropivacaine or to switch to normal saline. The primary endpoint was the time from the end of surgery until three discharge criteria were attained (adequate analgesia, independence from intravenous analgesics, and tolerance to 50% of shoulder motion targets). Patients were discharged home as early as the afternoon after surgery with their CISB using a portable infusion pump. Results:Patients receiving perineural ropivacaine (n = 16) attained all three discharge criteria in a median (10th–90th percentiles) of 21 (16–41) h, compared with 51 (37–90) h for those receiving perineural normal saline (n = 13, P < 0.001). Unlike patients receiving perineural ropivacaine, patients receiving perineural normal saline often required intravenous morphine, but still experienced a higher degree of pain and tolerated less external rotation. Conclusions:An ambulatory CISB considerably decreases the time until readiness for discharge after shoulder arthroplasty, primarily by providing potent analgesia that permits greater passive shoulder movement and the avoidance of intravenous opioids. Additional research is required to define the appropriate subset of patients and assess the incidence of complications associated with earlier discharge.

Evidence for a biopsychosocial influence on shoulder pain: Pain catastrophizing and catechol-O-methyltransferase (COMT) diplotype predict clinical pain ratings

&NA; The experience of pain is believed to be influenced by social, cultural, environmental, psychological, and genetic factors. Despite this assertion, few studies have included clinically relevant pain phenotypes when investigating interactions among these variables. This study investigated whether psychological variables specific to fear‐avoidance models and catechol‐O‐methyltransferase (COMT) genotype influenced pain ratings for a cohort of patients receiving operative treatment of shoulder pain. Patients (n = 58) completed questionnaires and had COMT genotype determined pre‐operatively. Then, shoulder pain ratings were collected 3–5 months post‐operatively. This cohort consisted of 24 females and 34 males, with mean age of 50.3 (SD = 15.0) and pre‐operative pain rating of 4.5/10 (SD = 1.8). The frequency of COMT diplotypes was 34 with “high COMT activity” (LPS group) and 24 with “low COMT activity” (APS/HPS group). Preliminary analysis indicated that of all the fear‐avoidance variables considered (fear of pain, kinesiophobia, pain catastrophizing, and anxiety), only pain catastrophizing was a unique contributor to clinical pain ratings. A hierarchical regression model indicated that an interaction between pain catastrophizing and COMT diplotype contributed additional variance in pre‐operative pain ratings. The pain catastrophizing × COMT diplotype interaction demonstrated predictive validity as patients with high pain catastrophizing and low COMT activity (APS/HPS group) were more likely (RR = 6.8, 95% CI = 2.8–16.7) to have post‐operative pain ratings of 4.0/10 or higher. Our findings suggest that an interaction between pain catastrophizing and COMT diplotype has the potential to influence pain ratings in patients seeking operative treatment of their shoulder pain.

Anatomy and biomechanics of the acromioclavicular and sternoclavicular joints.

The acromioclavicular and sternoclavicular joints have important soft-tissue static constraints that, based on biomechanical studies, imply a great deal of stability. The infrequency of significant symptoms following dislocations of these joints certainly highlights the fact that the dynamic muscle support is also very important. In performing resections of these joints for degenerative disease, our goal should be to preserve these important ligamentous supports by minimizing the amount of bone excised, as this seems to optimize results [84]. Precise isometric reconstruction of these complex, three-dimensional ligamentous structures merits further investigation in the laboratory and clinical settings.

Humeral fractures after shoulder arthroplasty.

Nine humeral fractures occurred subsequent to 499 shoulder arthroplasties that had been performed between December 1978 and November 1987 at the Mayo Clinic. The time from the arthroplasty to the fracture averaged thirty-nine months (range, eight to 101 months). Seven patients were women and two were men, and the average age was seventy years (range, forty-five to eighty-five years). The arthroplasties were performed for rheumatoid arthritis in five patients and for the sequelae of trauma in four. Six patients had advanced osteopenia, and two had had an ipsilateral total elbow arthroplasty. Six of the fractures were centered at the tip of the prosthesis; one fracture (type A) extended proximally, and five (type B) did not. The three remaining fractures (type C) involved the humeral shaft distal to the implant and extended into the distal humeral metaphysis. Four fractures healed with non-operative treatment. Two fractures that had unacceptable alignment were treated successfully with operative intervention. Three fractures that were treated with immobilization in a splint failed to heal; two of those fractures eventually united after a revision of the prosthesis and bone-grafting was performed, and one fracture remained ununited. Radial nerve palsy developed postoperatively in two patients, and it resolved within three months. Five patients had poor active motion before the fracture, and two of them had even less motion after the fracture was treated. Our experience suggests that long oblique and spiral fractures can be successfully treated non-operatively, provided that the skeletal alignment is acceptable.(ABSTRACT TRUNCATED AT 250 WORDS)

Interscalene perineural ropivacaine infusion:a comparison of two dosing regimens for postoperative analgesia.

Background and Objectives: A continuous interscalene nerve block with a perineural infusion of ropivacaine 0.2% at 8 mL/h has been shown to provide potent analgesia following moderately painful shoulder surgery. However, this high basal rate limits infusion duration for ambulatory patients who must carry the local anesthetic reservoir. We undertook this investigation to determine if the basal rate of an interscalene perineural ropivacaine infusion could be decreased by 50% with a concurrent 200% increase in patient-controlled bolus dose without compromising infusion benefits in ambulatory patients undergoing moderately painful orthopedic shoulder surgery. Methods: Preoperatively, patients (n = 24) received an interscalene perineural catheter and nerve block. Intraoperatively, patients received a standardized general anesthetic. Postoperatively, patients were discharged home with a portable infusion pump delivering ropivacaine 0.2% (500 mL reservoir) with a basal rate of 8 mL/h and a 2 mL patient-controlled bolus available each hour (“8/2” group, n = 12) or a 4 mL/h basal rate and 6 mL bolus dose (“4/6” group, n = 12), delivered in a randomized, double-blinded manner. Results: Patients in the 4/6 group had higher baseline pain scores only on postoperative day (POD) 2 (P = .011). However, these patients also experienced an increase in breakthrough pain incidence (5.8 boluses/d v 3.2, P = .035) and intensity (“worst” pain = 8/10 v 4/10, P < .05), sleep disturbances (2.0 v 0.0, P < .001), and a decrease in analgesia satisfaction (8 v 10, P = .003). Patients in the 8/2 group exhausted their local anesthetic reservoirs after a median of 61 hours, while the 4/6 group had a median of 131 mL remaining at infusion discontinuation after a median of 75 hours (P < .001). Conclusions: Following moderately painful ambulatory shoulder surgery, decreasing an interscalene perineural ropivacaine 0.2% basal rate from 8 to 4 mL/h provides similar baseline analgesia and lengthens infusion duration, but compromises other infusion benefits.

Carpal instability non-dissociative.

A retrospective study of 45 patients with symptoms of wrist pain and weakness with clinical evidence of instability is presented. These patients had normal intrinsic interosseous ligaments demonstrated arthrographically or surgically. They were followed for a minimum of 18 months and an average of 5.8 years. All patients demonstrated instability of the proximal carpal row which is referred to as carpal instability non-dissociative (CIND). Seven patients were treated non-operatively and 38 were treated operatively. Surgical management consisted of soft tissue reconstruction directed at the area of instability in 34 cases, joint levelling osteotomy in six, three of whom also had soft tissue reconstructions, and mid-carpal fusion in one. The overall good and excellent results were a disappointing 56% and there was no significant difference between the non-surgical and surgical groups. The best results were found in the ulna-minus CIND patients who underwent a joint levelling osteotomy, with 83% good and excellent results. CIND is associatedwith extrinsic ligamentous laxity; however, significant difficulty exists in locating the precise areas of maximum pathology. This accounts for the unpredictable results of treatment. As our understanding of the pathomechanics of CIND improves, the treatment will become more specific and the results should improve.

Continuous Passive Motion after Repair of the Rotator Cuff. A Prospective Outcome Study

Despite the apparent success of continuous passive motion after soft-tissue procedures or joint replacements, its effect after repair of the rotator cuff is still unknown. The purpose of this prospective, randomized outcome study was to compare the results of continuous passive motion with those of manual passive range-of-motion exercises after repair of the rotator cuff. Thirty-one patients (thirty-two rotator cuffs) were randomly assigned to one of two types of postoperative management: continuous passive motion (seventeen patients) or manual passive range-of-motion exercises (fifteen patients). There were seventeen women and fourteen men, and the mean age was sixty-three years (range, thirty to eighty years). The patients were followed for a mean of twenty-two months (range, six to forty-five months). Five tears of the rotator cuff were small, eighteen were medium, and nine were large. All of the operations were performed by one surgeon. The patients who were managed with continuous passive motion used the device for the first four weeks postoperatively. The patients who were managed with manual passive range-of-motion exercises were assisted by a trained relative, friend, or home-care nurse. After the four-week period, the two groups were managed similarly for two to five months. According to the Shoulder Pain and Disability Index, a valid and reliable self-administered questionnaire, the treatment was extremely successful in both groups. The overall score was excellent for twenty-seven shoulders (84 per cent), good for two (6 per cent), fair for two (7 per cent), and poor for one (3 per cent). With the numbers available, we could detect no significant differences (p > 0.05) between the two groups with respect to the score according to the Index, pain (according to a visual-analog scale), range of motion, or isometric strength. Manual passive range-of-motion exercises were more cost-effective than continuous passive motion. The limited number of physical-therapy visits associated with the manual passive range-of-motion exercises in the present study appeared to be more cost-effective than a traditional physical-therapy schedule of three visits per week. Postoperative therapy with continuous passive motion or manual passive range-of-motion exercises appears to yield favorable results after repair of a small, medium, or large tear of the rotator cuff.

The glenoid in shoulder arthroplasty.

Total shoulder arthroplasty is a common treatment for glenohumeral arthritis. One of the most common failure modes of total shoulder arthroplasty is glenoid loosening, causing postoperative pain, limitation of function, and potentially, the need for revision surgery. The literature has devoted considerable attention to the design of the glenoid component; efforts to better understand the biomechanics of the reconstructed glenohumeral joint and identify factors that contribute to glenoid component loosening are ongoing. This article reviews the current state of knowledge about the glenoid in total shoulder arthroplasty, summarizing the anatomic parameters of the intact glenoid, variations in component design and fixation, the mechanisms of glenoid loosening, the outcomes of revision surgery in the treatment of glenoid component failure, and alternative treatments for younger patients.