Houdek, Matthew T.

Background: Tendons are primarily acellular, limiting their intrinsic regenerative capabilities. This limited regenerative potential contributes to delayed healing, rupture, and adhesion formation after tendon injury. Purpose: To determine if a tendon’s intrinsic regenerative potential could be improved after the application of a purified exosome product (PEP) when loaded onto a collagen scaffold. Study Design: Controlled laboratory study. Methods: An in vivo rabbit Achilles tendon model was used and consisted of 3 groups: (1) Achilles tenotomy with suture repair, (2) Achilles tenotomy with suture repair and collagen scaffold, and (3) Achilles tenotomy with suture repair and collagen scaffold loaded with PEP at 1 × 10 12 exosomes/mL. Each group consisted of 15 rabbits for a total of 45 specimens. Mechanical and histologic analyses were performed at both 3 and 6 weeks. Results: The load to failure and ultimate tensile stress were found to be similar across all groups ( P ≥ .15). The tendon cross-sectional area was significantly smaller for tendons treated with PEP compared with the control groups at 6 weeks, which was primarily related to an absence of external adhesions ( P = .04). Histologic analysis confirmed these findings, demonstrating significantly lower adhesion grade both macroscopically ( P = .0006) and microscopically ( P = .0062) when tendons were treated with PEP. Immunohistochemical staining showed a greater intensity for type 1 collagen for PEP-treated tendons compared with collagen-only or control tendons. Conclusion: Mechanical and histologic results suggested that healing in the PEP-treated group favored intrinsic healing (absence of adhesions) while control animals and animals treated with collagen only healed primarily via extrinsic scar formation. Despite a smaller cross-sectional area, treated tendons had the same ultimate tensile stress. This pilot investigation shows promise for PEP as a means of effectively treating tendon injuries and enhancing intrinsic healing. Clinical Relevance: The production of a cell-free, off-the-shelf product that can promote tendon regeneration would provide a viable solution for physicians and patients to enhance tendon healing and decrease adhesions as well as shorten the time required to return to work or sports.

AbstractIntroductionEndoprosthetic or allograft reconstruction are the preferred reconstruction techniques for proximal humeral bone tumors. Failure of these reconstructions may occur, but historically revision is performed rarely due to the lack of reliable options. Reverse shoulder arthroplasty with an allograft prosthetic composite (rAPC) may provide a revision option. The purpose of the current study was to evaluate our institutional outcome of these procedures.MethodsEleven (6 male, 5 female) patients (mean age 51 ± 17 years) underwent revision of a failed oncologic reconstruction of the proximal humerus utilizing a rAPC. The most common indication for revision was subluxation (n = 6) and the most common previous implant was an endoprosthesis (n = 5).ResultsRevision resulted in improvements in shoulder elevation (39° vs. 62°, p = 0.02), external rotation (13° vs. 25°, p = 0.04), American Shoulder and Elbow Surgeons score (39 vs. 58, p = 0.004) and Musculoskeletal Tumor Society Scores (51% vs 69%, p = 0.002). There were 2 re‐revision procedures performed. One for an allograft fracture and one for allograft resorption and loosening.ConclusionsRevision with a rAPC can effectively restore patient function. Due to the complexity of the cases, we advocate for these procedures to be performed by subspecialty upper extremity surgeons trained in complex revision shoulder arthroplasty.

Background. Limb-salvage surgery combined with radiotherapy has become the primary treatment for soft tissue sarcomas of the extremity. Free functional latissimus flaps (FFLF) are an option to restore function in the setting of volumetric muscle loss. The purpose of the current study was to examine the use of FFLF in patients undergoing resection of thigh sarcoma. Methods. Twelve patients with a sarcoma involving the hamstring (n = 6), quadriceps (n = 5), or combined (n = 1) defects which included multiple muscle groups were reviewed. This included 9 males and 3 females with a mean age and body mass index of 56 ± 12 years and 31.3 ± 5.7 kg/m2. Results. The mean defect volume and operative time was 3,689 ± 2,314 cm3 and 587 ± 73 minutes. Following reconstruction, the mean knee range of motion (ROM), MSTS93 score, and muscle strength was 89 ± 24°, 90 ± 15%, and 4 ± 1; with 75% of patients ambulating without gait aids. Seven (58%) patients sustained a complication, namely, delayed wound healing (n = 2). Conclusion. Although there was a high incidence of complications, FFLF can restore active knee ROM and function, with most patients ambulating without gait aids following reconstruction of large oncologic defects in the thigh.

Aims Bone marrow-derived mesenchymal stem cells obtained from bone marrow aspirate concentrate (BMAC) with platelet-rich plasma (PRP), has been used as an adjuvant to hip decompression. Early results have shown promise for hip preservation in patients with osteonecrosis (ON) of the femoral head. The purpose of the current study is to examine the mid-term outcome of this treatment in patients with precollapse corticosteroid-induced ON of the femoral head. Methods In all, 22 patients (35 hips; 11 males and 11 females) with precollapse corticosteroid-induced ON of the femoral head underwent hip decompression combined with BMAC and PRP. Mean age and BMI were 43 years (SD 12) and 31 kg/m² (SD 6), respectively, at the time of surgery. Survivorship free from femoral head collapse and total hip arthroplasty (THA) and risk factors for progression were evaluated at minimum five-years of clinical follow-up with a mean follow-up of seven years (5 to 8). Results Survivorship free from femoral head collapse and THA for any reason was 84% and 67% at seven years postoperatively, respectively. Risk factors for conversion to THA included a high preoperative modified Kerboul angle (grade 3 or 4) based on preoperative MRI (hazard ratio (HR) 3.96; p = 0.047) and corticosteroid use at the time of decompression (HR 4.15; p = 0.039). The seven-year survivorship for patients with grade 1 or 2 Kerboul angles for conversion to THA for articular collapse, and THA for any reason, were 96% and 72%, respectively, versus THA for articular collapse and THA for any reason in patients with grade 3 or 4 Kerboul angles of 40% (p = 0.003) and 40% (p = 0.032). Conclusion At seven years, hip decompression augmented with BMAC and PRP provided a 67% survivorship free from THA in patients with corticosteroid-induced ON. Ideal candidates for this procedure are patients with low preoperative Kerboul angles and can stop corticosteroid treatment prior to decompression. Cite this article: Bone Jt Open 2021;2(11):926–931.

Background: Lymphedema is a chronic disease characterized by fluid buildup and swelling that can lead to skin and soft-tissue fibrosis and recurring soft-tissue infections. Literature with regard to the increased risk of complications following a surgical procedure in patients with lymphedema is emerging, but the impact of lymphedema in the setting of primary total hip arthroplasty (THA) remains unknown. The purpose of this study was to review outcomes following primary THA performed in patients with lymphedema compared with a matched cohort without lymphedema. Methods: Using our institutional total joint registry and medical records, we identified 83 patients (57 were female and 26 were male) who underwent THA with ipsilateral lymphedema. For comparison, these patients were matched 1:6 (based on sex, age, date of the surgical procedure, and body mass index [BMI]) to a group of 498 patients without lymphedema who underwent primary THA for osteoarthritis. Subsequently, postoperative complications and implant survivorship were evaluated for each group. The mean follow-up for each group was 6 years. Survivorship was compared between cohorts using Kaplan-Meier methodology and included both survivorship free of infection and survivorship free of reoperation or revision. Univariate Cox regression analysis was utilized to assess the association between patient factors for the time to event outcomes noted above. Results: In patients with a history of lymphedema, there was an increased risk of complications (hazard ratio [HR], 1.97; p < 0.01), including reoperation for any cause (HR, 3.16; p < 0.01) and postoperative infection (HR, 4.48; p < 0.01). The 5-year infection-free survival rate was 90.3% for patients with lymphedema compared with 97.7% for patients without lymphedema (p < 0.01). Conclusions: Patients with lymphedema are at increased risk for complications, including reoperation and infection, following primary THA. These data emphasize the importance of appropriate preoperative counseling in this population and should encourage efforts to identify methods to improve outcomes, including further investigation of the effects of preoperative optimization of lymphedema prior to THA and methods for improved perioperative management. Level of Evidence: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Background: Free flap coverage in the setting of a total knee arthroplasty is rare. The purpose of the current study was to evaluate the outcome of patients who underwent a free flap to assist with soft-tissue coverage following a complex total knee arthroplasty. Methods: The authors used their institutional total joint registry to retrospectively review patients undergoing a free soft-tissue flap in the setting of complex primary and revision total knee arthroplasty. Among 29,069 primary and 6433 revision total knee arthroplasties from 1994 to 2017, eight (0.02 percent) required a free flap for wound coverage. This included three primary total knee arthroplasties (0.01 percent) for posttraumatic arthritis and five revision total knee arthroplasties (0.07 percent) in the setting of infection. Median follow-up was 4 years. Results: Free flaps included vertical rectus abdominis (n = 3), anterior lateral thigh (n = 2), latissimus (n = 2), and transverse rectus abdominis (n = 1). There were no total flap losses; however, one patient required additional skin grafting. Reoperation occurred in six patients, of which four were revisions of the total knee arthroplasty for infection (n = 2) and tibial component loosening (n = 2). One patient ultimately underwent transfemoral amputation for persistent infection. Following reconstruction, there was improvement in the median Knee Society Score (49 versus 82; p = 0.03) and total range of motion between preoperative and postoperative assessments (70 degrees versus 85 degrees; p = 0.14). Conclusion: Free flap coverage in the setting of total knee arthroplasty was associated with a high rate of reoperation; however, the limb was able to be preserved in the majority of patients, with a reasonable functional outcome. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

AbstractIntroductionThe elbow is a rare location for primary and metastatic tumors in the upper extremity. The goal of reconstruction is to provide painless motion and stability for hand function. Total elbow arthroplasty (TEA) is commonly utilized, with either off‐the‐self components, modular segmental endoprosthesis, or allograft‐prosthesis composites (APC). The purpose of this study was to analyze and compare commonly utilized elbow reconstructions and report outcomes of (1) patient function and (2) implant survival and complications.MethodsWe reviewed 33 patients (18 females and 15 males) undergoing elbow arthroplasty for reconstruction of an underlying oncologic process including linked TEA (n = 22, 67%), APC (n = 9, 27%), and endoprosthesis (n = 2, 6%). The most common indication was metastatic disease (n = 17, 52%), with 24 patients (73%) presenting with a pathologic fracture.ResultsFive‐year implant survival was following elbow reconstruction was 88%. The mean most recent Mayo Elbow Performance Score and Musculoskeletal Tumor Society Score were 84 ± 18 and 78 ± 15%. Postoperative complications occurred in 15 elbows (45%), most commonly periprosthetic fracture (n = 5, 15%), leading to reoperation in six elbows (18%).ConclusionAlthough elbow arthroplasty is associated with a high incidence of complications, it provides a stable platform for upper extremity function in patients with oncologic processes of the elbow.

AimsOrthopaedic and reconstructive surgeons are faced with large defects after the resection of malignant tumours of the sacrum. Spinopelvic reconstruction is advocated for resections above the level of the S1 neural foramina or involving the sacroiliac joint. Fixation may be augmented with either free vascularized fibular flaps (FVFs) or allograft fibular struts (AFSs) in a cathedral style. However, there are no studies comparing these reconstructive techniques.MethodsWe reviewed 44 patients (23 female, 21 male) with a mean age of 40 years (SD 17), who underwent en bloc sacrectomy for a malignant tumour of the sacrum with a reconstruction using a total (n = 20), subtotal (n = 2), or hemicathedral (n = 25) technique. The reconstructions were supplemented with a FVF in 25 patients (57%) and an AFS in 19 patients (43%). The mean length of the strut graft was 13 cm (SD 4). The mean follow-up was seven years (SD 5).ResultsThere was no difference in the mean age, sex, length of graft, size of the tumour, or the proportion of patients with a history of treatment with radiotherapy in the two groups. Reconstruction using an AFS was associated with nonunion (odds ratio 7.464 (95% confidence interval (CI) 1.77 to 31.36); p = 0.007) and a significantly longer mean time to union (12 months (SD 3) vs eight (SD 3); p = 0.001) compared with a reconstruction using a FVF. Revision for a pseudoarthrosis was more likely to occur in the AFS group compared with the FVF group (hazard ratio 3.84 (95% CI 0.74 to 19.80); p = 0.109); however, this was not significant. Following the procedure, 32 patients (78%) were mobile with a mean Musculoskeletal Tumor Society Score 93 of 52% (SD 24%). There was a significantly higher mean score in patients reconstructed with a FVF compared with an AFS (62% vs 42%; p = 0.003).ConclusionSupplementation of spinopelvic reconstruction with a FVF was associated with a shorter time to union and a trend towards a reduced risk of hardware failure secondary to nonunion compared with reconstruction using an AFS. Spinopelvic fixation supplemented with a FVF is our preferred technique for reconstruction following resection of a sacral tumour. Cite this article: Bone Joint J 2021;103-B(8):1414–1420.

AbstractBackgroundCoverage of posterior trunk defects after tumor resection can be challenging due to the intricate anatomy. The keystone perforator island flap (KPIF) provides coverage of the defect without the need for distant flap coverage or microsurgery, matches the recipient's skin color and contour, and requires a short operative time.MethodsA retrospective review of all oncological back reconstructions with KPIF was performed at our institution. The patient comorbidities and surgical outcomes were collected.ResultsA total of 17 patients underwent 20 KPIF (15 single and 2 double) for back reconstruction. Surgical indications were sarcoma (n = 12) and melanoma (n = 5). The mean age at surgery was 47.3 years (SD 23.3). The flaps were located in the upper back (n = 8), paraspinal (n = 4), middle back (n = 6), and lower back (n = 2). The average wound size after sarcoma and melanoma excision were 231.6 ± 297.4 and 156.7 ± 269.7 cm2, respectively. Four patients required an additional planned skin graft and one patient underwent a simultaneous myocutaneous latissimus dorsi flap. The mean operative time, including tumor resection, was 256 min (SD 118). The median length‐of‐hospital stay was 3 days (Q1–3: 1–6.5) and the median follow‐up time was 35.3 months (Q1–3: 13.3–53.1). All flaps survived with minor surgical complications which included hematoma (n = 1), surgical site infection requiring debridement (n = 1), superficial wound dehiscence (n = 1), cellulitis (n = 1), and seroma (n = 1). The reconstructions were successful in 100% of patients.ConclusionsThe KPIF is a reliable and safe option for reconstruction of oncological back defects with minimal perioperative complications. This flap option avoids the use of free flaps and myocutaneous flaps for moderate‐sized back defects.

Abstract Background Foot and ankle soft tissue sarcomas (STS) are challenging for reconstruction due to limited surrounding soft tissue and weight‐bearing requirements. Currently, there is a paucity of data examining the outcome of flap reconstruction following resection of a foot and ankle sarcoma. Methods We reviewed 44 (31 female, 13 male) patients with STS arising from the ankle or foot which required coverage in the form of a free ( n = 21), pedicled ( n = 13), or rotational perforator flap ( n = 10). The mean tumor size was 6 ± 5 cm, with 39 (89%) patients receiving radiotherapy. The mean follow‐up was 10 ± 7 years. Results There were no cases of amputation due to flap failure, with a 10‐year limb salvage rate of 84%. Complications occurred in 19 (43%) patients, most commonly wound infections. There was no difference in the incidence of complications between patients undergoing a free flap and pedicled or perforator flap (odds ratio = 0.97, p = 1.0); with no difference in the mean Musculoskeletal Tumor Society (MSTS) score between patients with a free flap versus a pedicled/perforator flap (84% vs. 76%, p = 0.11). Conclusion Flap reconstruction is an essential part of limb salvage for foot and ankle STS. At final follow‐up nearly all the patients are ambulatory with an acceptable MSTS score.