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Biomedical subjects

Robert J Strauch

Publications and source records attributed to Robert J Strauch.

17 recordsLinked to original sources
PubMed2006

An in vitro analysis of ligament reconstruction or extension osteotomy on trapeziometacarpal joint stability and contact area.

PURPOSE: Painful instability of the minimally osteoarthritic thumb carpometacarpal (CMC) joint can be treated successfully by either ligament reconstruction or metacarpal extension osteotomy. The purpose of this study was to measure the laxity of cadaveric thumb CMC joints and to determine the influence of ligament reconstruction and metacarpal osteotomy on joint laxity and contact area. METHODS: The baseline laxity of CMC joints from 25 fresh-frozen human cadaveric specimens (average age, 42 y; range, 18-55 y) was measured in the position of lateral pinch on a custom-designed CMC joint laxity tester. Joint laxity was measured again after 2 surgical simulations consisting of either a metacarpal extension osteotomy (at 10 degrees and 15 degrees) or a simulated Eaton-Littler ligament reconstruction (including total, volar, and dorsal ligament reconstructions relative to the plane of the thumbnail). Contact area between the thumb metacarpal and trapezium during testing was determined using stereophotogrammetry. RESULTS: The 15 degrees extension osteotomy significantly reduced CMC joint laxity in the radial-ulnar, dorsal-volar, pronation-supination, and distraction directions in the position of lateral pinch. The 10 degrees osteotomy reduced laxity only in the dorsal-volar direction. The total ligament reconstruction significantly reduced joint laxity in the radial-ulnar, dorsal-volar, and pronation-supination directions. The dorsal ligament reconstruction reduced laxity in the dorsal-volar direction only; the volar ligament reconstruction reduced laxity in both dorsovolar and radioulnar directions. The 10 degrees and 15 degrees osteotomies produced a dorsal shift of the weighted centroid of contact on the metacarpal and trapezium, whereas the ligament reconstruction did not produce such an effect. CONCLUSIONS: In the position of lateral pinch the 15 degrees osteotomy and total ligament reconstruction significantly reduced laxity of the thumb CMC joint in all directions tested. The isolated dorsal or volar ligament reconstructions both reduced dorsal-volar laxity. Metacarpal extension osteotomy may stabilize the thumb CMC joint in lateral pinch to a degree similar to that of a standard ligament reconstruction.

Adolescent↗
PubMed2005

The biomechanical analysis of a tendon fixation device for flexor tendon repair.

PURPOSE: Stainless steel suture is high in tensile strength but is not widely used in flexor tendon repair because of difficulty with handling and knot tying. The purpose of this study was to examine the biomechanical characteristics of the single-strand multifilament stainless steel Teno Fix device (Ortheon Medical, Winter Park, FL) designed for zone II flexor digitorum profundus (FDP) tendon repair. METHODS: Sixty cadaveric flexor tendons were transected and randomized to receive a Teno Fix or 4-stranded (3-0 or 4-0 braided polyester) suture repair; all repairs were tested with and without a 5-0 monofilament polypropylene circumferential epitendinous suture. By using a material testing system all tendons were tested to failure in tension using a linear model with a loading rate of 1 mm/s. Stiffness, force, and energy at both 2-mm gap and peak force were calculated from the resulting force-displacement curves. RESULTS: The 2-mm gapping force was significantly greater for the Teno Fix and the 3-0 repairs than for the 4-0 repairs. The energy absorbed up to 2-mm gap was significantly greater for the Teno Fix, however, than for all suture repairs both with and without a circumferential suture. There was no statistically significant difference in peak force or energy absorbed at peak force between the Teno Fix and suture repairs; the average gap at peak force for all repairs was 5.2 mm. The addition of a circumferential suture increased the 2-mm gapping and peak forces of the Teno Fix repair to 54.5 N and 66.7 N, respectively. CONCLUSIONS: Increased strength and energy absorbed at 2-mm gap and ease of installation makes the Teno Fix a promising repair method.

Biomechanical Phenomena↗
PubMed2005

The effects of implant composition on extensor tenosynovitis in a canine distal radius fracture model.

PURPOSE: Dorsal plating of distal radius fractures with titanium plates has resulted in clinically observed tenosynovitis and tendon rupture. The goal of this study was to investigate whether titanium-based implants result in more extensor tendon inflammation than matched stainless-steel implants in a canine fracture model. METHODS: An osteotomy was created in the distal radius of 18 beagles and fixed with 2.7-mm 4-hole plates composed of commercially pure titanium, titanium alloy (Ti-Al6-V4), or 316L stainless steel. Animals were killed at an average of 4 months. Tendon gliding was assessed by applying a force at the extensor musculotendinous junction and noting gliding. Histologic grading (mild, moderate, severe) was based on cellular hypertrophy, hyperplasia, and leukocytic infiltration. RESULTS: Tendons glided freely in 100% stainless-steel specimens, 75% of titanium alloy, and 43% of commercially pure titanium groups. A severe inflammatory reaction was identified in 60% of the titanium alloy (Ti-A16-V4) group, 57% of the pure titanium group, and 0% of the stainless-steel group. CONCLUSIONS: Dorsal plating of the canine radius with commercially pure titanium or titanium alloy implants produced a greater inflammatory peritendinous response than matched stainless-steel implants.

Alloys↗
PubMed2005

Osseous sarcoidosis of the hand: pathologic analysis and review of the literature.

A destructive granulomatous process involving the right fifth metacarpal and the soft tissues of the right thumb and nose of an African-American woman without pulmonary disease is described. The initial biopsy examination of the metacarpal showed caseating and noncaseating granulomata. After a fifth-ray amputation the disease progressed, leading to the referral of the patient to our institution. A biopsy examination of this recurrence showed a predominance of solid noncaseating granulomata. The diagnosis of sarcoidosis was made on the basis of the morphology of the granulomata and by exclusion of infectious and neoplastic causes. Steroid therapy has resulted in cessation of clinical and radiographic disease progression at a 3-year clinical follow-up evaluation.

Amputation, Surgical↗
PubMed2005

Wrist denervation and the anterior interosseous nerve: anatomic considerations.

PURPOSE: Wrist denervation via resection of the distal anterior interosseous nerve (AIN) and the posterior interosseous nerve (PIN) is an effective treatment for chronic wrist pain. When performing this procedure through a dorsal approach we have been impressed by anatomic variations of the AIN. This has raised concerns about potential denervation of the pronator quadratus (PQ). The purpose of this study was to elucidate the anatomy of the AIN and PIN as encountered through a dorsal distal forearm incision. METHODS: Ten fresh-frozen cadavers were dissected. Before dissection radiographs were obtained to ensure accurate localization of the proximal ulnar head with a radiopaque marker. A dorsal approach to the distal forearm was made to identify the anatomy of the PIN and AIN. The location and diameter of all AIN branches were noted by using an operating stereoscopic microscope at x 25 magnification and a precision caliper. The PIN anatomy and size also were noted. RESULTS: The anatomy of the AIN was variable. The average AIN diameter proximal to the PQ was 1.5 mm. The average number of AIN motor branches was 4.2. The largest PQ motor branch was the first motor branch and was located at an average distance of 37.9 mm from the proximal ulnar head. The last motor branch was found an average of 23.9 mm from the proximal ulnar head. In 9 of 10 specimens the sensory branch tunneled radially through the distal PQ and innervated the periosteum of the volar distal radius. In 4 of 10 specimens a separate branch to the distal radioulnar joint was present. We found an average PIN diameter of 0.87 mm. CONCLUSIONS: Resection of the AIN at a point 4 cm proximal to the proximal point of the ulnar head would denervate completely the PQ in our cadaver population. Division of the AIN 2 cm proximal to the ulnar head would spare most of the PQ motor branches.

Aged↗
PubMed2004

Central slip tenotomy for the treatment of chronic mallet finger: an anatomic study.

PURPOSE: Tenotomy of the central slip, described by Fowler, can clinically improve chronic distal interphalangeal joint (DIP) extensor lag secondary to mallet finger (terminal tendon disruption). The goal of this study is to evaluate the potential of central slip tenotomy to restore DIP joint extension. METHODS: A mallet deformity was reproduced in 15 fresh-frozen cadaver fingers after the extensor tendon insertion was sectioned over the DIP joint. A suture anchor inserted at the terminal insertion was then secured to the extensor tendon over the middle phalanx to reconstruct the extensor mechanism. A 500-g weight attached to the proximal extensor tendon applied extensor tension. Central slip tenotomy was then performed. DIP extensor lags before and after tenotomy were recorded. RESULTS: After sectioning of the terminal tendon over the DIP joint the average amount of extensor tendon lag produced was 45 degrees. After central slip tenotomy was performed the average amount of extensor lag correction was 36 degrees (range, 30 degrees-46 degrees). CONCLUSIONS: Several clinical studies have shown that central slip tenotomy is an effective treatment for chronic mallet finger but may not fully restore DIP joint extension. Our data suggest that patients with a pre-existing extensor lag of greater than 36 degrees may not achieve full extension from central slip tenotomy, although extensor lags of up to 46 degrees may be corrected.

Adult↗
PubMed2004

Partially retained small finger flexor digitorum profundus function despite complete tendon loss in the forearm.

A case of traumatic laceration of the small finger flexor digitorum profundus (FDP) tendon in the distal forearm with retained partial active flexion at the small finger distal interphalangeal joint (DIP) joint is described. Tendinous interconnections between the ring and small FDP tendons and lumbrical muscles may permit partial FDP function at the DIP joint despite a complete deficit of the proximal tendon.

Biomechanical Phenomena↗
PubMed2004

Extensor mechanism slide for the treatment of proximal interphalangeal joint extension lag: an anatomic study.

PURPOSE: We describe a technique for correction of proximal interphalangeal joint (PIP) extensor lag secondary to angulation and/or shortening of proximal phalanx fractures. METHODS: Proximal phalanx fracture malunions with 2.5 mm of shortening, 5.0 mm of shortening, and apex volar angulation of 40 degrees were simulated in 15 cadaver fingers, creating PIP extensor lags. The metacarpophalangeal (MCP) joint was pinned in neutral. Transection of the ulnar and radial sagittal bands, the extensor digitorum communis (EDC) insertion on the MCP joint capsule, and the juncturae tendinae then was performed. The PIP extensor lag before and after each of the earlier-noted releases was recorded. The MCP joint then was freed and MCP hyperextension was recorded. With the MCP joint in neutral position the sagittal bands then were reapproximated with sutures and MCP extension was measured. RESULTS: The 2.5 mm of axial shortening, 5.0 mm of axial shortening, and 40 degrees of apex volar angulation fracture models produced an average extensor lag of 6.2 degrees , 25.8 degrees , and 42.5 degrees , respectively. Maximal correction of PIP extensor lag required transection of both sagittal bands, EDC insertion on the MCP capsule, and the juncturae tendinae with an average residual extensor lag of -0.8 degrees for the 2.5-mm shortening model, 0.7 degrees for the 5.0-mm shortening model, and 3.2 degrees for the 40 degrees -angulation model. The MCP joint hyperextension increased by 20 degrees to 30 degrees after the releases but decreased to only 1.8 degrees if the sagittal bands were reapproximated to the EDC tendon at their new resting position with the MCP joint in neutral position. CONCLUSIONS: In the cadaver model the PIP extensor lag can be improved substantially by transection of the sagittal bands, release of the EDC insertion on the MCP capsule, transection of the juncturae tendinae, and reapproximation of the sagittal bands to the EDC tendon.

Aged↗
PubMed2003

Sequential wear patterns of the articular cartilage of the thumb carpometacarpal joint in osteoarthritis.

PURPOSE: The thumb carpometacarpal (CMC) joint is a primary location for osteoarthritis (OA) in the body; however, articular cartilage thickness distribution during progression of OA in the joint has not been reported previously. Determining the cartilage wear patterns within the joint is important in understanding the etiology and treatment of thumb CMC joint OA. This study used cadaveric specimens to investigate the wear patters of the articular surfaces of the trapezium and thumb metacarpal. METHODS: A total of 104 fresh-frozen thumb CMC joints were radiographed, disarticulated, and visually staged for OA. Cartilage thickness maps of the trapezium and metacarpal were determined for each joint by using stereophotogrammetry. Average cartilage thickness maps for the trapezium and metacarpal were generated from all specimens for each of 4 stages of OA, showing the progression of cartilage thickness changes with disease. RESULTS: In normal joints, the surface-wide mean thickness of the articular layers is 0.8 +/- 0.2 mm for the trapezium and 0.7 +/- 0.2 mm for the metacarpal. The average thickness maps were analyzed by anatomic quadrant (dorsal-radial, dorsal-ulnar, volar-radial, volar-ulnar) within the 4 stages of OA. Corresponding quadrants also were compared across the increasing stages of OA. Results show that cartilage degradation is initiated in the radial quadrants of the metacarpal and progresses to the volar quadrants of the articular surface, while significant wear is seen on the dorsal-radial quadrant of the trapezium and progresses to the volar quadrants in late-stage osteoarthritis. CONCLUSIONS: These quantitative results on cartilage thinning agree with previous investigators' reports of high load bearing and low load bearing areas in the CMC joint during functional pinch and grasp positions. Understanding the progression of OA in the thumb CMC joint may aid in the surgical treatment of this disease.

Adolescent↗
PubMed2003

Simulated extension osteotomy of the thumb metacarpal reduces carpometacarpal joint laxity in lateral pinch.

PURPOSE: To assess the effect of an extension osteotomy of the thumb metacarpal on thumb carpometacarpal (CMC) joint laxity with respect to the lateral pinch position. METHODS: Seven fresh-frozen specimens were dissected. The metacarpal, trapezium, and trapezoid were removed en bloc and rigidly fixed proximally and distally. The laxity of each specimen was measured by cyclically loading the CMC joint in a custom-built laxity testing device designed to allow relative movement of the trapezium and first metacarpal in 4 directions. The position of the CMC joint in lateral pinch was used as the baseline joint position. An extension osteotomy then was simulated by flexing the metacarpal base 30 degrees, thus placing the joint in the relationship it would assume if an extension osteotomy was performed and the specimen was positioned in lateral pinch. Laxity measurements then were repeated. RESULTS: The simulated extension osteotomy reduced laxity in all directions tested: dorsal-volar (40% reduction), radial-ulnar (23% reduction), distraction (15% reduction), and pronation-supination (29% reduction). CONCLUSIONS: The beneficial clinical effects of a thumb metacarpal extension osteotomy may be partially due to reduced joint laxity in the position of lateral pinch.

Adolescent↗
PubMed2003

Radiography and visual pathology of the osteoarthritic scaphotrapezio-trapezoidal joint, and its relationship to trapeziometacarpal osteoarthritis.

PURPOSE: To determine and quantify the relationship of osteoarthritis (OA) in the trapeziometacarpal, scaphotrapezial, and scaphotrapezoidal joints; to ascertain the dependability of radiographic assessment of trapeziometacarpal, scaphotrapezial, and scaphotrapezoidal OA; to determine the articular topography of the scaphotrapezio-trapezoidal (STT) joint (composed of the scaphotrapezial and scaphotrapezoidal articulations) using stereophotogrammetry; and to characterize the articular wear patterns of STT OA. METHODS: Sixty-nine fresh-frozen human cadaveric hands were staged radiographically and by gross visual examination for the presence of OA in the trapeziometacarpal and STT joints. Twenty randomly selected joints also were evaluated to determine the topography of the STT joint using stereophotogrammetry. RESULTS: Concomitant severe osteoarthritic degeneration was found in the trapeziometacarpal and STT joint in 60% of our specimens. A correlation was found in the severity of OA in the trapeziometacarpal and STT joints. Radiographic and gross visual evaluation of STT OA concurred in 39% of our specimens. CONCLUSIONS: The prevalence of concomitant trapeziometacarpal and STT OA, and the uncertainty of radiographic evaluation of STT OA, indicate the need to visualize the STT joint intraoperatively to determine the true degree of degenerative changes present.

Carpal Bones↗
PubMed2003

The efficacy of silver nitrate cauterization for pyogenic granuloma of the hand.

PURPOSE: We report a series of pyogenic granulomas of the hand treated effectively in the office with silver nitrate cauterization. METHODS: Twelve patients with 13 pyogenic granulomas of the hand were treated. The average duration of symptoms was 2 months. Masses were removed bluntly, pressure was held proximal to the lesion to effect hemostasis, and the base of the lesion was cauterized with silver nitrate applicators. After treatment patients were instructed to keep the lesions absolutely dry for 2 weeks. RESULTS: Complete resolution of the pyogenic granuloma was achieved in 85% of patients after an average of 1.6 treatments (range, 1-3 treatments). CONCLUSIONS: Pyogenic granuloma of the hand can be treated simply and effectively with silver nitrate cauterization in the office setting.

Adult↗
PubMed2002

The role of flexor tenosynovectomy in the operative treatment of carpal tunnel syndrome.

BACKGROUND: We conducted a prospective, randomized study to evaluate the effect of flexor tenosynovectomy as an adjunct to open carpal tunnel release for the treatment of idiopathic carpal tunnel syndrome and reviewed the histological characteristics of the flexor tenosynovium to identify possible correlations between histopathology and symptoms. METHODS: Eighty-eight wrists in eighty-seven patients with idiopathic carpal tunnel syndrome were randomized to open carpal tunnel release with or without flexor tenosynovectomy. A validated self-administered questionnaire for the assessment of symptom severity and functional status was completed both before and after the operation to assess patient outcome. The study group included fifteen men and seventy-two women with a mean age of fifty-eight years. All patients were followed for a minimum of twelve months after the operation. Intraoperatively, the tenosynovium of all patients was graded on the basis of its gross appearance. Half of the wrists were then treated with a flexor tenosynovectomy through the operative incision, and the tenosynovium was graded histologically. Correlations were sought between the gross appearance of the tenosynovium and the preoperative and postoperative symptoms and functional status, between the histologic appearance of the tenosynovium and the preoperative and postoperative symptoms and functional status, and between the gross and the histologic findings. RESULTS: After the operation, both groups improved significantly with respect to symptom severity and functional status (paired t test), with no significant difference between the groups (unpaired t test). No significant correlation was found between the gross appearance of the tenosynovium and the preoperative or postoperative symptoms and functional status, between the histologic appearance of the tenosynovium and the preoperative or postoperative symptoms and functional status, or between the gross and the histologic findings. CONCLUSIONS: We observed neither an added benefit nor an increased rate of morbidity in association with the performance of a flexor tenosynovectomy at the time of carpal tunnel release. We identified no clinical correlations that might predict which individuals would benefit from flexor tenosynovectomy on the basis of either the gross (intraoperative) or histologic evaluation of the flexor tenosynovium. Our findings suggest that routine flexor tenosynovectomy offers no benefit compared with sectioning of the transverse carpal ligament alone for the treatment of idiopathic carpal tunnel syndrome.

Adolescent↗
PubMedDate not supplied

Vitallium radial head prosthesis for acute and chronic elbow fractures and fracture-dislocations involving the radial head.

This retrospective study aims to evaluate the radiographic, functional, and patient-derived outcomes of 16 patients who each received a Vitallium radial head prosthesis for unreconstructable acute fractures of the radial head, as well as previously treated fractures of the radial head associated with residual instability, pain, and stiffness. Follow-up averaged 33 months. A trend toward greater disability and poorer motion was noted in the delayed treatment group compared with the acute replacement group. Overall, the results were excellent in 5 patients, good in 10, and poor in 1, as determined by the Mayo Elbow Performance Score. All elbows were stable at follow-up, and no patient reported wrist pain. Four required further operative treatment of their elbow injuries. Metallic radial head arthroplasty yields satisfactory results in acute unreconstructable radial head fractures or as a salvage procedure for previously treated radial head fractures.

Acute Disease↗
PubMedDate not supplied

Posttraumatic elbow stiffness: evaluation and management.

Posttraumatic elbow stiffness is a common problem that is often difficult to manage. The goal of treatment is to restore a functional range of elbow motion (> or =30 degrees to 130 degrees ). Nonsurgical treatment includes physical therapy and splinting. If nonsurgical treatment has failed, the type of surgical treatment required depends on the extent of degenerative changes. When degenerative changes are absent or mild, soft-tissue release offers reliable increases in elbow motion. When moderate degenerative changes exist within the joint, debridement arthroplasty of osteophytes and soft tissue has shown some success with increase in joint motion. With advanced degenerative changes, the therapeutic options are more limited. Results from biologic resurfacing arthroplasty are unpredictable, and total elbow arthroplasty should be reserved for the lower-demand elbow in a physiologically older individual.

Algorithms↗