Evaluation of flexor digitorum superficialis function in adolescent baseball players.

Hypothesis and/or Background: Increased flexor digitorum superficialis (FDS) tendon activity can be a therapeutic target for elbow disorders in adolescent baseball players. The proportion of adolescent baseball players who can use FDS independently is unknown, and which finger is most often used remains unclear. This study investigated whether adolescent baseball players intentionally used FDS on each finger. Methods: Adolescent baseball players were recruited and assessed for FDS function for each finger using the standard technique. Results: Sixty-nine participants (mean age: 10.4 years) were recruited. Participants numbered 33, 56, 59, and 25 on the throwing side and those numbered 28, 46, 54, and 33 on the nonthrowing side could independently flex the proximal interphalangeal joint while holding their palms in the index, middle, ring, and small fingers, respectively. When assessing both throwing and nonthrowing participants, a significant number of participants could independently flex the proximal interphalangeals of the ring and middle fingers but had difficulty with the index and small fingers (P < .001). No significant difference was noted between the throwing and nonthrowing participants in any finger (P > .05). Discussion and/or Conclusion: One study reported that participating baseball players with elbow pain have more medial elbow joint space than those without pain symptoms. In another study on finger movements during pitching motion, the force of the thumb, index, middle, and ring fingers was greatest immediately before maximum external rotation. According to both reports, FDS function, especially in the index finger, can be a therapeutic target for medial-sided elbow injuries in adolescent baseball players.

ß2-Microglobulin Elevates COL5A1 mRNA in the Subsynovial Connective Tissue of Patients Receiving Hemodialysis With Carpal Tunnel Syndrome.

Background Although carpal tunnel syndrome (CTS) is frequently observed in patients undergoing long-term hemodialysis (HD), exactly how CTS arises is unknown. Here, we examined levels of COL5A1 in the subsynovial connective tissue (SSCT) of patients receiving HD and studied its potential regulation by ß2-microglobulin (Β2-MG) in SSCT-derived cells (SSCTCs). Methods We extracted SSCT samples from 67 patients with CTS (49 non-HD and 18 HD) during carpal tunnel release. The samples were subjected to quantitative polymerase chain reaction (qPCR) to determine COL5A1 expression. Further, to examine the potential regulation of COL5A1 expression by Β2-MG, SSCTCs were stimulated in the absence (control) or presence of 10 µg/ml Β2-MG. Results The HD group showed significantly elevated COL5A1 levels compared to the non-HD group (P=0.027). Moreover, treating SSCTCs with Β2-MG for 24 h increased the mRNA expression of COL5A1 relative to control conditions (P=0.013). Conclusions Elevated COL5A1 expression may form part of the mechanism underlying the development of CTS, and Β2-MG may play a role in promoting COL5A1 expression in HD patients.

Tenodesis with bone marrow venting under local anesthesia for recalcitrant lateral epicondylitis: results of 2 years of follow-up.

Hypothesis: We hypothesized that the treatment of recalcitrant lateral epicondylitis requires accurate identification of the painful area to promote remodeling of the degenerated extensor insertion and to stabilize the tendon origin during tendon healing. Thus, we performed tenodesis with bone marrow venting under local anesthesia for recalcitrant lateral epicondylitis. Methods: Twenty patients (21 elbows) were treated with bone marrow venting at the painful area of the lateral epicondyle of the elbow and tenodesis using 2 soft anchors lateral to the capitellum (immediately distal to the painful area) and were followed up for ≥2 years. Patients were assessed using the numerical rating scale for pain and the Quick Disabilities of the Arm, Shoulder, and Hand questionnaire, and objective evaluation included active range of motion. Results: The mean preoperative and postoperative pain scores were 7.5 and 0.5, respectively, indicating significant pain relief (P < .001). The mean preoperative and postoperative Quick Disabilities of the Arm, Shoulder, and Hand questionnaire scores were 44.2 and 1.0, respectively (P < .001). Two elbows had a slightly positive Thomsen test at the final visit. No recurrence of intra-articular symptoms induced by synovial fringe impingement was observed. Patients experienced more pain at the bone-tendon junction of extensors than at the tendon parenchyma. Conclusion: Tenodesis with bone marrow venting under local anesthesia was effective for subjective patient satisfaction and positive clinical outcomes at ≥2 years of follow-up in patients with recalcitrant lateral epicondylitis. Intra-articular symptoms can be improved by stabilization of the lateral soft tissue without treatment for intra-articular lesions.

Displaced isolated coronal shearing fracture of the trapezoid: a case report.

We present a case of a displaced isolated coronal shearing trapezoid fracture, treated with open reduction and internal fixation using a headless compression screw after temporary second metacarpal-trapezoid and trapezium-trapezoid ligament detachment. Complete functional recovery was achieved. For trapezoid fractures, lateral and oblique X-ray views in supination are important.

The Mechanical Strength of Side-to-Side Tendon Repair Using a Modified Krackow Technique.

Background: The purpose of the present study was to assess the biomechanical strength and properties of a modified Krackow technique for side-to-side tendon repair with a short overlap length. Methods: The flexor digitorum superficialis, flexor digitorum profundus, and flexor pollicis longus muscles were harvested from 10 fresh frozen cadavers. Overall, 60 tendon repairs were divided into four groups based on the suture technique: modified Krackow technique repair (KT); weave suture repair (WS); mattress suture repair (MS); and composite technique repair (CT), a combination of the modified Krackow and weave suture techniques. Single loading mechanical tests were performed, and the results for each suture technique were compared. Results: Ultimate loads for KT, WS, MS, and CT were 155 ± 45 N, 122 ± 18 N, 92 ± 31 N, and 163 ± 22 N, respectively. KT and CT had significantly higher ultimate loads than the other groups. However, the difference between the KT and CT groups in terms of ultimate load was not significant. Conclusions: Based on the results from the single loading tests, the use of the modified Krackow and composite techniques appeared to provide stronger fixation than that with the use of the weave and mattress sutures with a short overlap length.

Polymicrobial Extensor Tenosynovitis Including Mycobacterium chelonae Caused by a Dog Bite: A Case Report.

CASE: A nonimmunocompromised 77-year-old man was bitten in the hand by his dog; redness, swelling, and exudate developed. Despite debridement and medications administered at another hospital, his symptoms did not improve. He was referred to us after 3 months. Debridement and negative-pressure wound therapy was performed. Cultures were positive for multiple bacterial organisms, including Mycobacterium chelonae. Polymicrobial extensor tenosynovitis including M. chelonae was diagnosed. Clarithromycin was given for 7 months based on drug sensitivity. His symptoms did not recur. CONCLUSION: Mycobacterium chelonae infections after dog bites are rare; however, mycobacterial culture tests are important, especially if tissue shows granulomatous inflammation.

Flexor Tenosynovitis Caused by Mycobacterium arupense: A Case Report and Review of the Literature.

CASE: A 64-year-old man presented with swelling of his right hand and forearm. This swelling had been recurring for 5 years. He liked sea fishing and frequently injured his fingers with fishhooks. He had difficulty bending his right little and ring fingers for 2 years and experienced finger numbness for several months. We diagnosed nontuberculous mycobacterial flexor tenosynovitis after Mycobacterium arupense was detected in a tissue sample. After surgery and 2 years of multidrug therapy, he has been recurrence-free for 3 years. CONCLUSION: Nontuberculous mycobacteriosis should be considered in chronic tenosynovitis cases.

Bilateral Solitary Osteochondroma of the Bicipital Tuberosity Accompanied with Painful Clicking: A Case Report and Literature Review.

Although osteochondroma is a benign bone tumor often observed in daily practice, solitary osteochondroma of the bicipital tuberosity is rarely observed. Herein, we report a case of bilateral solitary osteochondroma of the bicipital tuberosity. A 76-year-old woman experienced crackling and painful clicking bilaterally in her proximal forearms during pronation-supination. X-ray imaging, computed tomography, and magnetic resonance imaging revealed that the symptom was caused by bilateral solitary osteochondroma of the bicipital tuberosity. Bone tumor resection was performed on both sides. After surgery, the symptoms improved. X-ray imaging performed 2 years after surgery revealed no tumor recurrence. When painful clicking occurs around the elbow joint, a solitary osteochondroma of the bicipital tuberosity should be suspected; this symptom should be examined, and the surgeon should consider surgery positively. Exposed subchondral bone may rub against, collide with, or impinge upon the ulna during forearm pronation-supination and induce pain.

A dorsal approach for the distal-to-proximal internal fixation of oblique scaphoid fractures.

INTRODUCTION: Two methods using cannulated headless screws can be used for scaphoid fractures: Inserting the screw through the distal fragment and then into the proximal fragment through a palmar approach under direct vision or fluoroscopic guidance and inserting the screw in the proximal-to-distal direction through a dorsal approach with fluoroscopic guidance. These methods are sometimes difficult to use in oblique fractures when trying to achieve screw fixation perpendicular to the fracture plane.The most common mechanism of injury in the scaphoid fracture is forceful wrist hyperextension and punching something. Less commonly, a direct blow to the wrist also can cause a fracture. The mechanism of fracture by a direct blow to the wrist is not completely clear. CASE PRESENTATION: We experienced two rare cases of scaphoid fracture in goalkeepers sustained when they saved a goal by contacting the soccer ball with the palm of their hand. Both fractures were proximal oblique fractures. We performed through a dorsal approach to insert the screws in the distal-to-proximal direction under direct vision assisted with fluoroscopy. Bone union was noted after surgery in both cases. They returned to their occupations without wrist pain.We investigated the relationship between the fracture line and wrist position using a fresh cadaver. The experiment revealed that the fracture line of the scaphoid matched the dorsal edge of the articular surface of the radius with the wrist in 30° of dorsiflexion and 20° of ulnar deviation. CONCLUSION: In this report, we reported rare cases of scaphoid fracture due to contact with the soccer ball on the palm. We propose a surgical approach for an oblique fracture of the proximal scaphoid that used guide wires and screws, but was performed through a dorsal, and not palmar, approach to insert the screws in the distal-to-proximal direction.We presume that coronal shear stress to the scaphoid bone occurred when the palm contacted the ball with the wrist positioned at 30° dorsiflexion and 20° ulnar deviation.

Effects of the Elbow Flexion Angle on the Radial Nerve Location around the Humerus: A Cadaver Study for Safe Installation of a Hinged External Fixator.

BACKGROUND: This study aimed to investigate whether the distance between the radial nerve and rotational center of the elbow joint when observing from the lateral surface of the humerus changes according to passive elbow joint flexion for safe external fixation with a hinged fixator of the elbow joint. METHODS: Twenty fresh-frozen cadaveric arms were dissected. The points where the radial nerve crosses over the posterior aspect of the humerus, crosses through the lateral center, and crosses over the anterior aspect of the humerus were defined in the lateral view of the elbow joint, using fluoroscopy, as R1, R2, and R3, respectively. The distances between the rotational center and each point on the radial nerve were measured when the flexion angle of the elbow joint was 10°, 50°, 90°, and 130°. RESULTS: The distances between the rotational center and R1, R2, and R3 were 118 mm, 94 mm, and 65 mm, respectively, when the flexion angle was 10°; 112 mm, 93 mm, and 74 mm, respectively, for 50°; 108 mm, 93 mm, and 77 mm, respectively, for 90°; and 103 mm, 94 mm, and 83 mm, respectively, for 130°. The distance between the rotational center and R2 was constant regardless of the flexion angle. With elbow joint extension, the distances between R1 and R3 increased; the safe zone, a region where the radial nerve would not be located on the humerus, was the smallest in extension. When the elbow joint was flexed, the distances between R1 and R3 decreased; the safe zone was the largest in flexion. CONCLUSIONS: This study showed that the radial nerve location on the humerus varied based on the flexion angle of the elbow joint; the safe zone may change. A half-pin can be likely inserted safely, avoiding the elbow joint extension position.

Osteochondritis dissecans of the fourth proximal interphalangeal joint in a Japanese drummer.

We report a rare case of osteochondritis dissecans involving the fourth proximal interphalangeal joint in a young Japanese drummer. We treated it successfully with the removal of loose body and drilling of the donor site.

Anatomical Cadaver Study of the Hotchkiss Over-the-Top Approach for Exposing the Anteromedial Facet of the Ulnar Coronoid Process: Critical Measurements and Implications for Protecting the Median Nerve.

PURPOSE: To measure distances from anatomical landmarks to the median nerve, and estimate the length of the flexor-pronator/flexor carpi ulnaris (FCU) detachment necessary to expose the anteromedial facet of the ulnar coronoid process (UCP) using the Hotchkiss over-the-top approach. METHODS: Dissections were made of 20 fresh-frozen cadaveric upper limbs. Measurements were made of the shortest distance from the medial epicondyle to the median nerve, the distance from the medial epicondyle to the median nerve in line with the flexor-pronator/FCU interval, the shortest distance from the apex of the UCP to the median nerve, and the length of the flexor-pronator/FCU detachment necessary to expose the anteromedial facet of the UCP. Measurements were also made of the length of the ulnar insertion of the brachialis muscle and the shortest distances from the proximal and distal insertions of the brachialis muscle to the median nerve. RESULTS: The distances and lengths were as follows: medial epicondyle to median nerve, 31 ± 3 mm; in line with the flexor-pronator/FCU interval, 43 ± 5 mm; from the apex of the UCP to the median nerve, 7 ± 2 mm; the detachment necessary to expose the UCP, 47 ± 6 mm; the ulnar insertion of the brachialis muscle, 27 ± 4 mm; and the proximal and distal insertions of the brachialis muscle to the median nerve, 14 ± 2 mm and 5 ± 1 mm, respectively. CONCLUSIONS: The length of the flexor-pronator/FCU detachment necessary to expose the anteromedial facet of the UCP was similar to the distance from the medial epicondyle to the median nerve in line with the flexor-pronator/FCU interval. The distance from the distal insertion of the brachialis muscle to the median nerve was 5 mm. CLINICAL RELEVANCE: The results of our study provide information on important points for surgeons to consider when performing distal exposure using the Hotchkiss over-the-top approach.

Quantified Mechanical Properties of the Deltoid Muscle Using the Shear Wave Elastography: Potential Implications for Reverse Shoulder Arthroplasty.

The deltoid muscle plays a critical role in the biomechanics of shoulders undergoing reverse shoulder arthroplasty (RSA). However, both pre- and postoperative assessment of the deltoid muscle quality still remains challenging. The purposes of this study were to establish a novel methodology of shear wave elastography (SWE) to quantify the mechanical properties of the deltoid muscle, and to investigate the reliability of this technique using cadaveric shoulders for the purpose of RSA. Eight fresh-frozen cadaveric shoulders were obtained. The deltoid muscles were divided into 5 segments (A1, A2, M, P1 and P2) according to the muscle fiber orientation and SWE values were measured for each segment. Intra- and inter-observer reliability was evaluated using intraclass correlation coefficient (ICC). To measure the response of muscle tension during RSA, the humeral shaft was osteotomized and subsequently elongated by an external fixator (intact to 15 mm elongation). SWE of the deltoid muscle was measured under each stretch condition. Intra- and inter-observer reliability of SWE measurements for all regions showed 0.761-0.963 and 0.718-0.947 for ICC(2,1). Especially, SWE measurements for segments A2 and M presented satisfactory repeatability. Elongated deltoid muscles by the external fixator showed a progressive increase in passive stiffness for all muscular segments. Especially, SWE outcomes of segments A2 and M reliably showed an exponential growth upon stretching (R2 = 0.558 and 0.593). Segmental measurements using SWE could be reliably and feasibly used to quantitatively assess the mechanical properties of the deltoid muscle, especially in the anterior and middle portions. This novel technique based on the anatomical features may provide helpful information of the deltoid muscle properties during treatment of RSA.

Anatomic cadaveric study of the extensile extensor digitorum communis splitting approach for exposing the ulnar coronoid process.

BACKGROUND: The extensile extensor digitorum communis (EDC) splitting approach can access the ulnar coronoid process (UCP), which can be used to treat terrible triad injuries. The present study anatomically examined the extensile EDC splitting approach for exposing the UCP. METHODS: Twenty fresh frozen cadaveric upper limbs were dissected. The splitting length of the EDC and detachment length of the extensor carpi radialis brevis (ECRB)-extensor carpi radialis longus (ECRL)-brachioradialis (BR) origin were measured to expose the UCP. The distance between the most distal site of the EDC splitting and the point at which the posterior interosseous nerve (PIN) crosses the anterior aspect of the radial shaft, and the distance between the most proximal site of the ECRB-ECRL-BR origin detachment and the point at which the radial nerve crosses the anterior aspect of the humeral shaft were measured. RESULTS: The splitting length of the EDC was 45.4 ± 4.8 mm, the detachment length of the ECRB-ECRL-BR origin was 30.2 ± 4.7 mm, the distance between the distal site of the EDC splitting and PIN was 10.6 ± 6.1 mm (minimum distance, 1.1 mm), and the distance between the proximal site of the ECRB-ECRL-BR origin detachment and the radial nerve was 49.5 ± 9.7 mm (minimum distance, 31.7 mm). CONCLUSIONS: The extensile EDC splitting approach can sufficiently expose the UCP. However, splitting must be performed carefully because the most distal site of the EDC splitting is close to the point at which the PIN crosses the anterior aspect of the radial shaft (average distance, 10 mm; minimum distance, 1 mm).

A Cadaver Study of Median-to-Radial Nerve Transfer for Radial Nerve Injuries.

PURPOSE: To assess the anatomic feasibility of a median-to-radial nerve transfer in cadaver limbs and to quantify the number of axons present in the cut ends of the involved donor and recipient nerves. METHODS: Ten fresh frozen cadaveric upper limbs were dissected. We investigated whether the flexor carpi radialis (FCR) branch/flexor digitorum superficialis (FDS) branch (donor nerve) reached the posterior interosseous nerve (PIN)/extensor carpi radialis brevis (ECRB) branch (recipient nerve) without tension. We also investigated the length of the transected supinator fascia for FCR-posterior interosseous nerve transfer and the FDS-ECRB positional relationship using the epicondyle line and the midline of the forearm as axes. The findings were used for these 2 types of nerve transfer with evaluation closer to the target muscles. The distance between the point at which the FDS and ECRB branches met and the point at which the ECRB branch entered the muscle was measured. After nerve coaptation, the axon number was determined by histological evaluation. RESULTS: In all limbs, the FCR and FDS branches reached the PIN and the ECRB branch without tension. The transected supinator fascia was 17 (3-25) mm long. The point at which the FDS branch reached the ECRB branch [corrected] was 48 (23-65) mm distal to the epicondyle line and approximately 23 (18-27) mm radial to the midline of the forearm. The distance between the point at which the FDS and ECRB branches met and the point at which the ECRB branch entered the muscle was 27 (17-40) mm. The mean axon numbers were FCR, 1501 (932-3022); PIN, 5162 (4325-7732); FDS, 885 (558-962); and ECRB, 548 (433-723). CONCLUSIONS: The FCR branch could be transferred to the PIN [corrected] and the FDS to the ECRB branch in all limbs without tension. CLINICAL RELEVANCE: We provide anatomical and histological information for median-to-radial nerve transfer.

Total wrist arthrodesis with wrist fusion rod in patients with rheumatoid arthritis.

OBJECTIVES: This study aims to retrospectively review the short-term surgical outcome of wrist fusion using wrist fusion rod (WFR). PATIENTS AND METHODS: Six wrists of four female patients (mean age 56 years; range 51 to 62 years) with advanced stage rheumatoid arthritis of Larsen IV or V were performed total wrist fusion using WFR. Clinical outcome was assessed using a numeric rating scale of pain satisfaction level. Bony fusion, correction of palmar subluxation and ulnar deviation, rod bending angle, wrist fusion angle, and complications were assessed from radiographs. RESULTS: All wrists achieved painless wrist stability with bony fusion of the radiocarpal joint. Both the palmar subluxation and ulnar deviation were corrected in all patients. Two radiographic complications were observed: rod fracture in one patient and a radiolucent line in proximal metacarpal bone in another patient. Both complications might have occurred as a result of instability of the third carpometacarpal joint, but neither influenced clinical outcome. Wrist fusion angle was smaller than rod bending angle at final observation. CONCLUSION: Wrist fusion using WFR is an option for the treatment of advanced stage rheumatoid arthritis of wrist. According to our experience, the stability of third carpometacarpal joint should be assessed before surgery, and this joint should be fused if required. The bending angle of the intramedullary rod does not directly form the wrist fusion angle in contrast to the case with a dorsal wrist fusion plate.

Accuracy of specimen-specific nonlinear finite element analysis for evaluation of radial diaphysis strength in cadaver material.

The feasibility of a user-specific finite element model for predicting the in situ strength of the radius after implantation of bone plates for open fracture reduction was established. The effect of metal artifact in CT imaging was characterized. The results were verified against biomechanical test data. Fourteen cadaveric radii were divided into two groups: (1) intact radii for evaluating the accuracy of radial diaphysis strength predictions with finite element analysis and (2) radii with a locking plate affixed for evaluating metal artifact. All bones were imaged with CT. In the plated group, radii were first imaged with the plates affixed (for simulating digital plate removal). They were then subsequently imaged with the locking plates and screws removed (actual plate removal). Fracture strength of the radius diaphysis under axial compression was predicted with a three-dimensional, specimen-specific, nonlinear finite element analysis for both the intact and plated bones (bones with and without the plate captured in the scan). Specimens were then loaded to failure using a universal testing machine to verify the actual fracture load. In the intact group, the physical and predicted fracture loads were strongly correlated. For radii with plates affixed, the physical and predicted (simulated plate removal and actual plate removal) fracture loads were strongly correlated. This study demonstrates that our specimen-specific finite element analysis can accurately predict the strength of the radial diaphysis. The metal artifact from CT imaging was shown to produce an overestimate of strength.

Bilateral carpal tunnel syndrome due to gouty tophi: conservative and surgical treatment in different hands of the same patient.

Gouty tophi are an uncommon cause of carpal tunnel syndrome. We describe a case of bilateral carpal tunnel syndrome due to gouty tophi. Gouty tophi in the right wrist developed slowly, but developed acutely in flexor tendons in the left wrist. Symptoms were numbness and finger movement dysfunction in both hands. The right hand was treated surgically, while the left hand was treated by medication. Both hands improved under a well-controlled serum uremic acid level.

Accuracy of specimen-specific nonlinear finite element analysis for evaluation of distal radius strength in cadaver material.

BACKGROUND: Distal radius fracture, which often occurs in the setting of osteoporosis, can lead to permanent deformity and disability. Great effort has been directed toward developing noninvasive methods for evaluating the distal radius strength, with the goal of assessing fracture risk. The aim of this study was to evaluate distal radius strength using a finite element model and to gauge the accuracy of finite element model measurement using cadaver material. METHODS: Ten wrists were obtained from cadavers with a mean age of 89.5 years at death. CT images of each wrist in an extended position were obtained. CT-based finite element models were prepared with Mechanical Finder software. Fracture on the models was simulated by applying a mechanical load to the palm in a direction parallel to the forearm axis, after which the fracture load and the site at which the fracture began were identified. For comparison, the wrists were fractured using a universal testing machine and the fracture load and the site of fracture were identified. RESULTS: The fracture load was 970.9 N in the finite element model group and 990.0 N in the actual measurement group. The site of the initial fracture was extra-articular to the distal radius in both groups. The finite element model was predictive for distal radius fracture when compared to the actual measurement. CONCLUSION: In this study, a finite element model for evaluation of distal radius strength was validated and can be used to predict fracture risk. We conclude that a finite element model is useful for the evaluation of distal radius strength. Knowing distal radius strength might avoid distal radius fracture because appropriate antiosteoporotic treatment can be initiated.