Single Incision Distal Biceps Repair With Hemi-Krackow Suture Technique: Surgical Technique and Early Outcomes.

BACKGROUND: Many surgical methods exist for distal biceps repair. We present the technique and early outcomes of a series of distal biceps repairs completed with a novel suturing technique utilizing a hemi-Krackow locking stitch at the tendon-bone interface. METHODS: A retrospective review was performed of patients who underwent primary distal biceps repair using a single anterior incision with 2 suture anchors utilizing a hemi-Krackow stitch. With both anchors, a locking stitch along the tendon edge was complimented by the other strand passing through the central aspect of the distal tendon and advanced to pull the tendon edge down to the bone with appropriate tension. Patients with revision surgery and the use of allograft were excluded. Clinical outcomes included elbow range of motion and grip strength. All patients completed a Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire and reported satisfaction level, pain level, and any postoperative complications. RESULTS: Fourteen patients with an average age of 51.3 years (range, 27.8-66.4 years) were included in the study. The dominant arm was injured in 9 cases. At an average of 16.4 months' follow-up (range, 6.8-34.3 months), all patients had elbow range of motion of 0° to >130°, and grip strength was 101.5% of the uninjured arm (range, 70.6%-121.4%). The Average QuickDASH score was 6.5 (range, 0-36.5). CONCLUSION: Single incision biceps repair with suture anchor fixation using our hemi-Krackow stitch provided a strong repair allowing easy tensioning of the biceps tendon to bone and showed satisfactory functional outcomes at early follow-up. No patients required revision surgery, and there was only 1 case of transient nerve complaints.

Effects of platelet-derived growth factor-BB on the metabolic function and morphologic features of equine tendon in explant culture.

OBJECTIVE: To evaluate the effects of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) on the metabolic function and morphologic features of equine superficial digital flexor tendon (SDFT) in explant culture. Animals-6 euthanized horses (2 to 5 years old). METHODS: Forelimb SDFT explants were cultured for 6 days as untreated control specimens or treated with rhPDGF-BB (1, 10, 50, or 100 ng/mL of medium). Treatment effects on explant gene expression were evaluated via real-time PCR analysis of collagen type I, collagen type III, PDGF-A, and PDGF-B mRNA. Explants were assayed for total collagen, glycosaminoglycan, and DNA content; histologic changes were assessed via H and E staining and immunohistochemical localization of collagen types I and III. RESULTS: No morphologic or proliferative changes were detected in tendon explant sections. After high-dose rhPDGF-BB treatment, gene expression of collagen types I and III was increased and decreased, respectively. Expression of PDGF-A and PDGF-B mRNA was significantly increased at 24 hours, but later decreased to have few or negative autoinductive effects. Although PDGF gene expression waned after 48 hours of culture, collagen type I gene expression was significantly increased at 48 hours and reached peak value on day 6. Glycosaminoglycan and DNA content of explants were unchanged with rhPDGF-BB treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that rhPDGF-BB use may be of benefit in the repair of equine tendon, particularly through induction of collagen type I mRNA. Positive autoinductive effects of PDGF-BB in equine SDFT explants were detected early following culture medium supplementation, but these diminished with time.

Nucleotide structure of equine platelet-derived growth factor-A and -B and expression in horses with induced acute tendinitis.

OBJECTIVE: To characterize the nucleotide sequence of equine platelet-derived growth factor (PDGF)-A and -B and analyze temporal expression of these genes in equine tendon after induced tendinitis injury. Animals-18 mature horses. PROCEDURES: Genes for equine PDGF-A and -B were reverse transcribed and sequenced from synovial tissue mRNA obtained from a 3-year-old horse. Collagenase-induced lesions were created in the tensile region of the superficial digital flexor tendon in 14 horses; 3 horses served as uninjured control animals. Tendons were harvested and total RNA was isolated from experimental horses 1, 2, 4, 8, and 24 weeks after collagenase injection. Temporal gene expression for PDGF-A and -B was determined by use of quantitative PCR analysis. RESULTS: Equine PDGF-A shared 83.8% sequence and 87.5% peptide homology with human PDGF-A, with a discrepancy of 70 bp from the human sequence. Equine PDGF-B was similar in length to the human gene, sharing 90.3% and 91.7% nucleotide and peptide identity, respectively. Expression of PDGF-A mRNA in collagenase-induced tendinitis lesions was unchanged, compared with expression for normal control tendon, and remained steady throughout the 24-week study. Expression of PDGF-B mRNA decreased over time, and the expression at 24 weeks was significantly reduced, compared with expression in normal and acutely injured tendon. CONCLUSIONS AND CLINICAL RELEVANCE: Injured tendon mounts a minimal constitutive PDGF-A or -B mRNA response. Serial exogenous treatment with either PDGF isoform within the first 2 to 4 weeks after tendon injury may bolster the meager PDGF paracrine-autocrine intrinsic response to injury.