Augmented Ulnar Collateral Ligament Repair With Structural Bioinductive Scaffold: A Biomechanical Study

BACKGROUND

Elbow ulnar collateral ligament (UCL) repair with suture brace augmentation shows good time-zero biomechanical strength and a more rapid return to play compared with UCL reconstruction. However, there are concerns about overconstraint or stress shielding with nonabsorbable suture tape. Recently, a collagen-based bioinductive absorbable structural scaffold has been approved by the Food and Drug Administration for augmentation of soft tissue repair.

PURPOSE/HYPOTHESIS

This study aimed to assess the initial biomechanical performance of UCL repair augmented with this scaffold. We hypothesized that adding the bioinductive absorbable structural scaffold to primary UCL repair would impart additional time-zero restraint to the valgus opening.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight cadaveric elbow specimens-from midforearm to midhumerus-were utilized. In the native state, elbows underwent valgus stress testing at 30o, 60o, and 90o of flexion, with a cyclical valgus rotational torque. Changes in valgus rotation from 2- to 5-N·m torque were recorded as valgus gapping. Testing was then performed in 4 states: (1) native intact UCL-with dissection through skin, fascia, and muscle down to an intact UCL complex; (2) UCL-transected-distal transection of the ligament off the sublime tubercle; (3) augmented repair with bioinductive absorbable scaffold; and (4) repair alone without scaffold. The order of testing of repair states was alternated to account for possible plastic deformation during testing.

RESULTS

The UCL-transected state showed the greatest increase in valgus gapping of all states at all flexion angles. Repair alone showed similar valgus gapping to that of the UCL-transected state at 30° (P = .62) and 60° of flexion (P = .11). Bioinductive absorbable scaffold-augmented repair showed less valgus gapping compared with repair alone at all flexion angles (P = .021, P = .024, and P = .024 at 30°, 60°, and 90°, respectively). Scaffold-augmented repair showed greater gapping compared with the native state at 30° (P = .021) and 90° (P = .039) but not at 60° of flexion (P = .059). There was no difference when testing augmented repair or repair alone first.

CONCLUSION

UCL repair augmented with a bioinductive, biocomposite absorbable structural scaffold imparts additional biomechanical strength to UCL repair alone, without overconstraint beyond the native state. Further comparative studies are warranted.

CLINICAL RELEVANCE

As augmented primary UCL repair becomes more commonly performed, use of an absorbable bioinductive scaffold may allow for improved time-zero mechanical strength, and thus more rapid rehabilitation, while avoiding long-term overconstraint or stress shielding.

Bifocal avulsion fracture and fixation of the patellar tendon: a case report

Acute distal patella tendon avulsion from the tibial tubercle (TT) is a relatively rare injury that is usually described in the adolescents or elderly population in their 7th or 8th decades. Bifocal avulsion fractures of the patella tendon from the TT and the distal pole of the patella are exceptionally rare in adults. In this case report, we present a 52-year-old healthy old male who was treated for bifocal avulsion of the patellar tendon with open reduction and internal fixation augmented with two ULTRATAPE sutures. To our knowledge, this is the first case report to describe this injury in a healthy middle-aged patient.

A modified minimally invasive osteotomy for hallux valgus enables reduction of malpositioned sesamoid bones

BACKGROUND

The current minimally invasive distal metatarsal osteotomy for hallux valgus (HV) is V-shaped, which prevents the correction of the rotational metatarsal head deformity and reduction of the sesamoid bones. We sought to determine the optimal method for sesamoid bone reduction during HV surgery.

METHODS

We reviewed the medical records of 53 patients who underwent HV surgery between 2017 and 2019 using one of three techniques: open chevron osteotomy (n = 19), minimally invasive V-shaped osteotomy (n = 18), and a modified straight minimally invasive osteotomy (n = 16). The sesamoid position was graded using the Hardy and Clapham method on weight-bearing radiographs.

RESULTS

When compared to open chevron and V-shaped osteotomies, the modified osteotomy resulted in significantly lower postoperative sesamoid position scores (3.74 ± 1.48, 4.61 ± 1.09, and 1.44 ± 0.81, respectively, P < 0.001). Furthermore, the mean change in postoperative sesamoid position score was greater (P < 0.001).

CONCLUSION

The modified minimally invasive osteotomy was superior to the other two techniques in correcting HV deformity in all planes, including sesamoid reduction.

Less is better than more with resection of periacetabular tumors - A retrospective 16 years study and literature review

Introduction

Wide resections of periacetabular tumors create a sizeable bony defect that inevitably results in severe loss of function. Reconstruction of such defects usually requires using large metal implants, a feature associated with considerable surgery extension and complications. The aim of this study is to report resection with no reconstruction of the bony defect. In this retrospective study, we reviewed a consecutive series of 16 patients diagnosed with malignant periacetabular tumors and underwent en-bloc resection without reconstructing their remaining bone defect.

Methods

Records were reviewed of 16 consecutive patients diagnosed with malignant periacetabular tumors and underwent en-bloc resection without reconstructing their remaining bony defect. Measurements included: the duration of surgery, blood loss, hemoglobin levels and the need for blood transfusions, data on other hospitalization characteristics, and intraoperative and postoperative complications.

Results

Sixteen patients with malignant periacetabular bone tumors and extensive bone destruction underwent wide periacetabular tumor resection with a mean follow-up of 75 months and a mean age of 53 years. The average HOOS score was 46 (range: 20 to 76), and the mean MSTS score was 13% (range: 0 to 15). The mean operative time was 4.1 h, and the mean blood loss was 1200 ml. At their most recent follow-up, patients had a mean shortening of their operated extremity of 4.8 cm, and all could ambulate with assisting devices.

Conclusion

Wide resection of periacetabular tumors without reconstruction provides acceptable levels of function and was associated with shorter surgical time, less blood loss and fewer postoperative complications compared to resection with reconstruction. Therefore, this approach may be considered a viable surgical option in patients with an extensive malignant periacetabular.

Level III

Retrospective study.

[NOVEL CONCEPTS AND CHANGES IN TOTAL JOINT ARTHROPLASTY IN THE 21ST CENTURY]

INTRODUCTION

Total joint arthroplasty (TJA) is amongst the most common elective orthopedic surgeries. Since their introduction in 1951 there have been changes not only in prosthesis design and surgical approaches, but also in patient management, anesthesia, drug regimen and robotic arm assistance. These changes led to advancement in patient safety and shorter hospitalization. Today TJA is accessible for a wider age and function range of patients, which has led to an exponential growth in the number of procedures conducted.

Comparison of Platelet-Rich Plasma Treatment and Partial Plantar Fasciotomy Surgery in Patients with Chronic Plantar Fasciitis: A Randomized, Prospective Study

Platelet-Rich Plasma (PRP) injection has become a desirable alternative to Partial Plantar Fasciotomy (PPF) surgery and steroid injection for patients with chronic plantar fasciitis (CPF) due to its potential for shorter recovery times, reduced complications, and similar activity scores. As such, we compared PRP treatment to PPF surgery in patients with CPF. Between January 2015 and January 2017, patients were randomly divided into two groups, a PRP treatment group, and a PPF group. All procedures were performed by a single foot and ankle fellowship-trained specialist surgeon. Visual Analog Score (VAS) and Roles-Maudsley Scale (RM) were collected during the preoperative visit and 3, 6, and 12 months postoperatively. The patients were also closely followed by a physiotherapist. There were 16 patients in each group after four patients refused to participate. Patients in the PPF had low Roles-Maudsley Scale (RM) scores compared to the PRP group one-year after treatment (3.77 vs. 2.72, p < 0.0001). Both procedures showed a reduction in RM scores during the follow-up year (9 to 1.62 for PPF and 8.7 to 2.4 for PRP). There was no significant change in VAS pain between the two groups (p = 0.366). Patients treated with PRP injection reported a significant increase in their activity scores, shorter recovery time, and lower complication rates compared to PPF treatment. Moreover, with respect to existing literature, PRP may be as efficient as steroid injection with lower complication rates, including response to physical therapy. Therefore, PRP treatment may be a viable option before surgery as an earlier line treatment for CPF. Level of Clinical Evidence: II.

Thousand shades of gray - The role of imaging display in diagnosis of occult scaphoid fractures - A pilot study

Introduction

Most hospitals and clinics utilize commercial grade displays for viewing wrist radiographs. There is no evidence regarding the role of the imaging display used to evaluate the radiographs. The aim of this study was to compare the rates of scaphoid fracture diagnosis by commercial grade and medical grade displays.

Methods

Wrist radiographs of patients that had clinical signs of scaphoid fracture without findings on plain radiography (suspected scaphoid fractures) were retrospectively collected from ER department and interpreted for radiographic signs of fracture by four orthopedics seniors commercial grade and medical grade displays. The difference in fracture diagnosis rates were studied. Inter- and intra-observer variability were also studied.

Results

Study population comprised of 175 high quality wrist radiographs were interpreted. Mean 48.25 (27%) scaphoid fractures were observed on commercial grade display compared to 66 (38.2%) on medical grade display (p = 0.076). The total inter-observer agreement could be defined as a moderate agreement (κ = 0.527, Accuracy = 0.77). Total agreement between all observers were observed in 86 (49.1%) cases compared to 89 (50.9%) cases when reviewing X-rays on commercial and medical displays, respectively.

Discussion

The scaphoid fracture detection rate on medical grade display was not statistically higher compared to non-medical grade displays, but we did find a tendency toward medical grade display. We found that in a substantial number of cases, our observers recognize signs of fracture that were initially evaluated as "suspected fracture" by the ER physicians. As a pilot study, we found evidence that support the need for a prospective study designed to compare the observations to a gold standard modality, such as MRI. We believe utilizing medical grade displays can increase the rate of diagnosis in cases of clinically suspected scaphoid fractures and better manage the clinical scenario of a suspected scaphoid fracture.

Radiographic Bone Healing in Minimally Invasive Floating Metatarsal Osteotomy for Neuropathic Plantar Metatarsal Head Ulcers - A Retrospective Cohort Study

Minimally invasive floating metatarsal osteotomy is an option for treating neuropathic ulcers under the metatarsal heads. This study presents the radiographic results of the floating metatarsal osteotomy. We reviewed files and radiographs at least 4 months after a floating metatarsal osteotomy in patients with diabetic neuropathy. In 71 osteotomies in 54 patients with late onset diabetes (mean age 61 ± 9, mean HbA1c 7.9 ± 1.9%), the primary ulcer healed within 3.5 ± 1.4 weeks. Of 66 osteotomies where radiographs were available 10 had non-union (15%, all asymptomatic), 15 (23%) had hypertrophic callus formation and 41 (62%) had normal union. One patient developed an ulcer under the hypertrophic callus. This necessitated callus resection. Asymptomatic non-union may happen in 15% of floating osteotomies, but the osteotomies appear to be relatively safe and effective for neuropathic plantar metatarsal head ulcers. Hypertropic callus causing local re-ulceration is rare and can be managed surgically.

Arthroscopic Treatment of Mild/Borderline Hip Dysplasia with Concomitant Femoroacetabular Impingement-Literature Review

Purpose of Review

This literature review aims to survey the current knowledge about the management FAI in the setting of borderline hip dysplasia.

Recent Findings

With better understanding, hip arthroscopy has recently been advocated for treating mild or borderline hip dysplasia (BDH) with concomitant femoroacetabular impingement (FAI) despite early studies that condemned its use. Recent outcome data have demonstrated that hip arthroscopy is a viable option in BDH, with and without FAI, and has been gaining wider acceptance. Hip arthroscopy can address the concomitant soft tissue and bony intra-articular pathologies and obviate the necessity for other surgeries. Moreover, hip arthroscopy may be used as an adjuvant treatment to other procedures such as a periacetabular osteotomy (PAO).

Summary

Hip arthroscopy for BDH is an evolving procedure with promising short- and mid-term outcomes. The combination of BDH and FAI is becoming recognized as a problem in its own right, requiring dedicated treatment.

Expandable Proximal Femoral Nail versus Gamma Proximal Femoral Nail for the treatment of hip reverse oblique fractures

BACKGROUND

Reverse oblique intertrochanteric fractures are classified by the AO/OTA as 31A3 and account for 2-23% of all trochanteric fractures. The Gamma 3-Proximal Femoral Nail (GPFN) and the Expendable Proximal Femoral Nail (EPFN) are among the various devises used to treat this fracture. The aim of this study was to compare outcomes and complication rates in patients with AO/OTA 31A1-3 fractures, treated by either a GPFN or an EPFN.

PATIENTS AND METHODS

A total of 67 patients (40 in the GPFN group and 27 in the EPFN group, average age 78.8 years) were treated in our institution between July 2008 and February 2016. Data on postoperative radiological variables, including peg location and tip-apex distance (TAD), as well as orthopedic complications, such as union rate, surgical wound infection and cut-outs rates were also recorded, along with the incidence of non-orthopedic complications and more surgical data. Functional results were evaluated and quantified using the Modified Harris Hip Score (MHHS) and by the Short Form 12 Mental Health Composite questionnaire (SF-12 MHC) in order to assess the quality of life.

RESULTS

The total prevalence of postoperative orthopedic complications including postoperative infection showed a significant difference with a p-value of 0.016 in favor of the EPFN group. Nonetheless, the frequency of revision did not differ between the two groups, being 0.134. The main orthopedic complication in both groups was head cut-out of the GPFN lag screw and the EPFN expendable peg, which was 20% and 7.4%, respectively, and required a revision surgery using a long nail or total hip replacement (THR). However, the average TAD did not significantly differ between groups which might be due to a relatively low cohort to reach a significant difference. Nonunion rate of 5% occurred solely in the GPFN group, with similar results of intraoperative open reduction between both groups. The EPFN group achieved better scores in both questionnaires (p = 0.027 and p = 0.046, respectively). Both the MHHS and SF-12 MCS values significantly differed between groups, with the EPFN group achieving better scores than the GPFN group in both questionnaires (p = 0.027 and p < 0.05, respectively).

CONCLUSIONS

According to this study, the EPFN yields better results in comparison with the GPFN, with relatively less complications rate, for the treatment of unstable reverse oblique pertrochanteric fracture. In light of this results, we conclude that the EPFN might be as good as GPFN for the treatment of reverse oblique intertrochanteric fractures.

LEVEL OF EVIDENCE

Level III retrospective study. The local institutional review board of the Tel Aviv Medical Center approved this study and all the surgeries were done exclusively in this institution.

Bipolar hemiarthroplasty may reduce cerebrovascular accidents and improve early weight-bearing in the elderly after femoral neck fracture

Cerebrovascular accidents (CVA) in the elderly population after femoral neck fracture remain great concern for physicians. Specifically, surgical fixation techniques, such as bipolar hemiarthroplasty (HA) and internal fixation play a significant role in influencing the occurrence of postoperative CVA in the elderly population.In order to identify 2 cohorts, we used a rigid selection process based on our institution's database. The cohorts were comprised of a HA cohort and a cannulated screw cohort, of which underwent femoral neck surgery, performed by 3 fellowship trained surgeons from 2003 to 2014. Risk factors were documented and measured, including Coumadin use and hypertension, and postoperative complications such as CVA and death rate were also recorded. A P-value of <.05 was determined to be statistically significant.A power analysis was performed and achieved a power of 0.95. We found a non-significant reduction in CVA for bipolar HA (3.6% CVA vs 0.0% in the non-CVA group, P = .48) and a non-significant increase in CVA for cannulated screw use (7.6% CVA vs 14.4% in the non-CVA group, P = .11). In addition, we found a significant difference in terms of weight-bearing status at 6-weeks postoperatively (0.95 vs 2.0, P < .0001), favoring the bipolar HA group.Among the advantages of bipolar HA surgery, surgeons should consider its value in reducing the occurrence of postoperative CVA. Furthermore, patients who underwent bipolar HA had improved weight-bearing status postoperatively compared with cannulated screw fixation.

Amputation versus Primary Nonoperative Management of Chronic Osteomyelitis Involving a Pedal Digit in Diabetic Patients

BACKGROUND

The preferred primary treatment of toe osteomyelitis in diabetic patients is controversial. We compared the outcome of primary nonoperative antibiotic treatment versus digital amputation in patients with diabetes-related chronic digital osteomyelitis.

METHODS

We conducted a retrospective medical record review of patients treated for digital osteomyelitis at a single center. Patients were divided into two groups according to initial treatment: 1) nonoperative treatment with intravenous antibiotics and 2) amputation of the involved toe or ray. Duration of hospitalization, number of rehospitalizations, and rate of below- or above-the-knee major amputations were evaluated.

RESULTS

The nonoperative group comprised 39 patients and the operative group included 21 patients. The mean ± SD total duration of hospitalization was 24.05 ± 15.43 and 20.67 ± 15.97 days, respectively (P = .43). The mean ± SD number of rehospitalizations after infection recurrence was 2.62 ± 1.63 and 1.67 ± 1.24, respectively (P = .02). During follow-up, the involved digit was eventually amputated in 13 of the 39 nonoperatively treated patients (33.3%). The rate of major amputation (above- or below-knee amputation was four of 39 (10.3%) and three of 21 (14.3%), respectively (P = .69).

CONCLUSIONS

Despite a higher rate of rehospitalizations and a high failure rate, in patients with mild and limited digital foot osteomyelitis in the absence of sepsis it may be reasonable to offer a primary nonoperative treatment for digital osteomyelitis of the foot.

MICA: A Learning Curve

Techniques of minimally invasive bunion surgery have become increasingly popular in recent years. However, the learning curve involved in mastering these innovative techniques has not been described. To address this issue, a trained foot and ankle surgeon in a university hospital operated on 50 patients using the minimally invasive Chevron and Akin procedure over the course of 3 years, from January 2016 through December 2018. Surgery duration and x-ray exposure were documented. Results showed that surgery duration decreased from >2 hours in the first cases to a mean of ∼45 minutes in the third year. This learning curve plateaued by the 21st patient. The number of intraoperative fluoroscopy studies used decreased substantially over the first 27 surgeries, at which point the learning curve plateaued. In summary, it took about 27 procedures for an inexperienced surgeon to acquire the skill of performing minimally invasive Chevron and Akin osteotomy.

Combined endoscopic and mini-open repair of chronic complete proximal hamstring tendon avulsion: a novel approach and short-term outcomes

To evaluate the outcome of a novel, combined endoscopic and mini-open repair (CEMR) of a chronic complete retracted proximal hamstring tendon avulsion (PHA). A retrospective case series of a single-surgeon database for all patients, with a minimum of 1-year follow-up, who underwent CEMR between July 2015 and September 2019 was performed. Patients were evaluated for their functional outcome using the Perth Hamstring Assessment Tool (PHAT). At the latest follow-up, patients were evaluated for their muscle strength, subjective satisfaction and post-operative complications. Twelve patients who underwent endoscopic surgery for chronic PHA were identified, of which seven patients underwent CEMR. After exclusion of one patient from the study due to an open claim for health insurance, six patients (five males) with a mean age of 48 years (range 20-61 years) were evaluated. The mean time from injury to surgery was 12 months (range 2-43 months). At a mean follow-up of 28 months (range 12-55 months), the average PHAT score was 73 (range 70-80). The mean subjective activity level percentage improved from 34 (range 20-50) pre-surgery to 81 (range 75-90) post-surgery. The mean strength of the quadriceps, hamstring at 30°, and hamstring at 90° of the operated leg compared to the uninjured leg did not differ significantly. One patient underwent adhesiolysis 1 year after the index procedure for treatment of subcutaneous adhesions. CEMR is a viable and safe option for the treatment of chronic complete proximal hamstring tears, with good to excellent short-term functional outcome. Level of evidence: IV.

Proximal Derotation Phalangeal Osteotomy for Medial First Toe Diabetic Ulcer

BACKGROUND

Foot ulcers are a common complication in diabetic patients. Mild callus formation due to a plantar pressure can lead to an ulcer formation with potentially hazardous sequelae. Eliminating the pressure from the ulcer is essential for a proper healing process. Proximal derotation phalangeal osteotomy is a relatively simple procedure that can redistribute the planter pressure points over the hallux.

METHODS

Thirteen patients underwent proximal derotation phalangeal osteotomy to relieve the bony pressure causing an ulcer in the first toe, which was refractory to non-operative treatment. Twelve patients had diabetes type 2 and one had Charcot-Marie-Tooth disease.

RESULTS

Ulcers were completely resolved in all 13 patients in an average time of 4.3 (range 2-8) weeks. Four patients (31%) had mild complications that resolved well. No further surgery was required at 1-year follow-up.

CONCLUSION

Proximal derotation phalangeal osteotomy enabled ulcer healing in refractory cases.

LEVEL OF EVIDENCE

Level III retrospective study.

The Efficacy of Labral Reconstruction: A Systematic Review

Background:

With a greater understanding of the importance of the acetabular labrum in the function of the hip, labral repair is preferred over debridement. However, in some scenarios, preservation or repair of the labrum is not possible, and labral reconstruction procedures have been growing in popularity as an alternative to labral resection.

Purpose:

To provide an up-to-date analysis of the literature to determine the overall efficacy of labral reconstruction when compared with labral repair or resection.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

PubMed, Embase, and MEDLINE databases were searched for literature regarding labral reconstruction in the hip before July 21, 2020. The results were screened and evaluated by 2 reviewers, and a third reviewer resolved any discrepancies. The final studies were evaluated using the MINORS (Methodological Index for Non-randomized Studies) score.

Results:

There were 7 comparative studies that fit the inclusion criteria, with 228 hips from 197 patients. The mean follow-up was 34.6 months, and the mean age of all patients was 38.34 years. There were slightly more female patients than male patients (105 vs 92). Arthroscopic reconstruction was performed in 86% of studies (6/7); open surgical techniques, in 14% (1/7). A variety of grafts was used in the reconstructions. The indications for labral reconstruction and outcome measures varied in these publications. Nine patients were lost follow-up, and 6 patients converted to total hip replacement postlabral reconstruction. The assessment of these comparative studies illustrated statistically equivalent results between labral reconstruction and labral repair. Comparisons of labral reconstruction with labral resection also showed statistically equivalent postoperative patient-reported outcome scores; however, the rates of conversion to total hip arthroplasty were significantly higher in the population undergoing resection.

Conclusion:

The review of current available comparative literature, which consists entirely of level 3 studies, suggests that labral reconstruction does improve postoperative outcomes but does not demonstrate superiority over repair. There may, however, be benefit to performing labral reconstruction over resection owing to the higher rate of conversion to total hip arthroplasty in the labral resection group.

Midterm Outcomes and Satisfaction After Hip Arthroscopy Are Associated With Postoperative Rehabilitation Factors

Background:

Arthroscopic hip-preservation surgery is commonly performed to address nonarthritic sources of hip pain in young, active individuals. However, there is little evidence to support postoperative rehabilitation protocols, including the most appropriate frequency and length of individual formal physical therapy sessions. There is also a lack of information to look at patients’ perceived value of their home program/self-practice in relation to outcomes.

Purpose:

To investigate postoperative rehabilitation factors after hip arthroscopy related to formal physical therapy and home program/self-practice and their correlation with patient outcomes and satisfaction.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 125 patients who underwent hip arthroscopy for femoroacetabular impingement syndrome and a labral tear (75 men) were included. The mean age was 34.6 ± 14.4 years, and the mean follow-up time was 4.9 ± 1.6 years. Hip Outcome Score–Activities of Daily Living subscale (HOS-ADL) scores, overall satisfaction scores, and factors related to supervised physical therapy and home program/self-practice were collected. Correlations between continuous variables and differences in the length of individual formal physical therapy and patients’ rating of the importance of their home program/self-practice between those who would and those who would not undergo surgery again were assessed.

Results:

The frequency and length of individual formal physical therapy sessions were significantly correlated with postoperative HOS-ADL scores (r = 0.22, P = .014; and r = 0.24, P = .007, respectively) and level of satisfaction (r = 0.24, P = .007; and r = 0.21, P = .02, respectively). The length of individual formal physical therapy sessions was significantly greater in those who noted they would undergo surgery again (35.3 vs 26.3; P = .033). A significant correlation was identified between the rating of the importance of their home program/self-practice and postoperative HOS-ADL scores (r = 0.29; P = .001) and their level of satisfaction (r = 0.23; P = .009). There was a significant difference in the rating of the importance of their home program/self-practice between those who would undergo surgery again and those who would not (8.9 vs 7.8; P = .007).

Conclusion:

Surgeons and physical therapists should emphasize the value of home program/self-practice when it comes to outcomes and may want to encourage their patients to participate in more frequent, longer, formal physical therapy sessions.

Subspinal impingement: clinical outcomes of arthroscopic decompression with one year minimum follow up

PURPOSE

This study was designed to (1) evaluate the clinical outcomes after arthroscopic subspinal decompression in patients with hip impingement symptoms and low AIIS, and to (2) assess the presence of low anterior inferior iliac spine on the pre-operative radiographs of patients with established subspinal impingement diagnosed intra-operatively.

METHODS

Retrospective analysis of patients who underwent arthroscopic subspinal decompression has been performed. The indications for surgery were femoroacetabular impingement (FAI), or subspinal impingement. Pre-operative radiographs were assessed for anterior inferior iliac spine type. Intra-operative diagnosis of low anterior inferior iliac spine was based on the level of anterior inferior iliac spine extension relative to the acetabulum and the presence of reciprocal labral and chondral lesions. In patients where low anterior inferior iliac spine was not diagnosed on pre-operative radiographs, the pre-operative radiographs were re-read retrospectively to assess missed signs of low anterior inferior iliac spine.

RESULTS

Thirty-four patients underwent arthroscopic subspinal decompression between 2012 and 2015. The patients were followed for a median of 25 months (13-37 months). Intra-operatively, grade 2 anterior inferior iliac spine was found in 27 patients and grade 3 anterior inferior iliac spine was found in 7 patients. MHHS, HOS, and HOSS scores increased from median (range) pre-operative scores of 55 (11-90), 48 (20-91) and 20 (0-80) to 95 (27-100), 94 (30-100) and 91 (5-100), respectively (p < 0.0001, p = 0.001, p < 0.0001, respectively). Pre-operative diagnosis of low AIIS was made in 6/34 patients via AP radiographs. On retrospective analysis of pre-operative radiographs, signs of low AIIS were still not observed in 21/34 (61.8%) patients.

CONCLUSIONS

Arthroscopic subspinal decompression of low AIIS yielded significantly improved outcome measures and high patient satisfaction at a minimum of 13 months follow-up. Low AIIS is often under-diagnosed on AP pelvis and lateral frog radiographs and if left untreated, may result in unresolved symptoms and failed procedure.

LEVEL OF EVIDENCE

IV.

Distal Chevron Osteotomy vs The Simple, Effective, Rapid, Inexpensive Technique (SERI) for Mild to Moderate Isolated Hallux Valgus: A Randomized Controlled Study

BACKGROUND

Hallux valgus is a common foot deformity that leads to functional disability with serious sequelae. Minimally invasive surgery is often used to treat hallux valgus in order to reduce wound complications and improve recovery time. The objective of this study was to compare a Simple, Effective, Rapid, Inexpensive (SERI) technique with a simple Chevron technique in patients with minimum of 1-year follow-up.

METHODS AND MATERIALS

Between the years 2014-2015, we performed a prospective study comparing the SERI minimally invasive technique to treat symptomatic hallux valgus with a standard chevron osteotomy technique. All procedures were performed by a single fellowship trained foot and ankle surgeon. Twenty-one patients were randomized to the SERI cohort and 15 to the standard Chevron technique.

RESULTS

The mean preoperative intermetatarsal angle (IMA) of the SERI group was 14.8 ± 1.9 (11.9-22.9). The mean preoperative IMA of the Chevron control group was 13.3 ± 2.3 (10.4-18.2) (p = 0.038). The mean IMA two weeks after the surgery was 6.0 ± 2.3 (2.4-12) in the SERI group, and 6.1 ± 3 (2.6-13.1) in the control group. At the two-week and 1-year follow-up, there was no significant difference found in the IMA between the two groups (p = 0.871). The mean hallux valgus angle reduction was 11.85 ± 4.88 (3-20.8) and 11.09 ± 6.51 (- 1.1 to 22.5) in the SERI and Chevron groups, respectively (p = 0.69). Neither groups reported symptomatic transfer metatarsalgia throughout the follow-up period. The SERI group had increased metatarsophalangeal joint (MTPJ) motion (p < 0.001); however, all other parameters with similar.

CONCLUSION

The SERI technique provided comparable outcomes at up to 1-year follow-up when compared with a standard Chevron osteotomy for moderate hallux valgus. This study demonstrated good reproducible results using the SERI technique for moderate hallux valgus.

LEVEL OF EVIDENCE

Level II Prospective Study.

TRIAL REGISTRATION

Approved by local IRB at MMC.

Preoperative planning and surgical technique for optimizing internal fixation of posterior malleolar fractures: CT versus standard radiographs

BACKGROUND

A proper reduction and internal fixation of posterior malleolar fractures can be challenging, as intraoperative fluoroscopy often underestimates the extent of the fracture. Our aim was to assess the value of a modified classification system for posterior malleolar fractures, which is based on computed tomography (CT) images, optimizing screw trajectory during fluoroscopic-guided surgery, and to compare it to the Lauge-Hansen classification system to the CT-based classification.

METHODS

A retrospective review of all ankle fracture operations from January 2014 to December 2016 was performed. Fractures were included if a CT scan was performed within 1 week of the surgery, and the posterior malleolar fragment occupied one third or more of the antero-posterior talar surface or jeopardize the ankle stability. Eighty-five adult ankle fractures with posterior malleolar fragments were included in this study. Fractures were categorized into one of three types, namely "postero-lateral," "postero-medial," or "postero-central," according to the location of the fracture fragment on axial CT image. An optimal trajectory angle for a single-lag screw fixation was measured on the CT cut between a central antero-posterior line and the line intersecting the posterior fragment perpendicular to the major fracture line. Mean trajectory angles were calculated for each fracture type. Fractures were also categorized according to the Lauge-Hansen system.

RESULTS

The mean trajectory angle was 21° lateral for "postero-lateral" fragments, 7° lateral for "postero-central" fragments, and 28° medial for "postero-medial" fragments (p < 0.01 for comparisons among the groups). The range of trajectory angles within each group was about 10°, as compared to about 20° within each Lauge-Hansen type. There were no differences in trajectory angle among the Lauge-Hansen groups (p > 0.05 for all comparisons).

CONCLUSIONS

There are 3 distinct anatomic subgroups of posterior malleolar fragments, each with an ideal screw trajectory that needs to be used in order to achieve an optimal reduction and fixation.

Postoperative Weightbearing Protocols After Arthroscopic Surgery for Femoroacetabular Impingement Does Not Affect Patient Outcome: A Comparative Study With Minimum 2-Year Follow-up

PURPOSE

To evaluate the effects of immediate postoperative weightbearing protocols after hip arthroscopy for femoroacetabular impingement (FAI) with minimum 2-year follow-up, as measured by patient-reported outcome measures and satisfaction rates.

METHODS

Between January 2011 and June 2016, patients undergoing hip arthroscopy for FAI and labral tears were reviewed. Exclusion criteria was previous hip pathology or arthroscopy, active Workers' Compensation claims, and concomitant pathologies impeding weightbearing. Patients who were operated on before September 2013 were treated with 3 weeks of postoperative non-weightbearing (NWB), with weightbearing as tolerated (WBAT) thereafter. From October 2013, patients were allowed immediate postoperative WBAT.

RESULTS

A total of 351 hip arthroscopic surgeries were performed; 133 of these patients met the inclusion criteria. Of the 133 included patients, 69 were in the NWB group and 64 were in the WBAT group. No differences were found in terms of sex (P = .603) or age (P = .241). No differences were found in postoperative scores (the Modified Harris Hip Score was 84.5 [range 79-89] for NWB vs 86.7 [78-89] for WBAT [P = .0.523], and the Hip Outcome Score was 83.1 [78-88] vs 88.4 [80-90], respectively; P = .130). Subjective rates of improvement, satisfaction score and the will to undergo surgery again did not differ between the groups (P = .674, P = .882, P = .730). The rate of subjects who met or exceeded the MCID in the NWB and WBAT groups was 82.6% and 81.2% for the Modified Harris Hip Score (P = .838) and 79.7% and 82.8% for the Hip Outcome Score (P = .647). There were no reported complications. Limitations include the possibility of the study being underpowered.

CONCLUSIONS

After a 2-year minimum follow-up, patient-reported outcome measures and satisfactory rates with immediate weightbearing after hip arthroscopy for isolated FAI syndrome and labral tears do not differ significantly from results after strict NWB rehabilitation protocols. Revising weightbearing restrictions may allow for a more comfortable rehabilitation process after arthroscopic hip surgery for FAI and labral repair.

LEVEL OF EVIDENCE

Level 3 - case-control study.

A combined endoscopic and open surgical approach for chronic retracted proximal hamstring avulsion

Proximal hamstring avulsion is an uncommon injury which usually requires surgical intervention. When possible, primary surgical fixation is recommended. In chronic hamstring avulsion with significant retraction of the tendon, hamstring reconstructions using an autograft or allograft are required in order to bridge the gap. This is mainly performed using an open surgical technique. We describe a combined endoscopic and open surgical approach to hamstring reconstruction surgery.

Does capsular closure influence patient-reported outcomes in hip arthroscopy for femoroacetabular impingement and labral tear?

Capsulotomy is necessary to facilitate instrument manoeuvrability within the joint capsule in many arthroscopic hip surgical procedures. In cases where a clear indication for capsular closure does not exist, surgeon's preference and experience often determines capsular management. The purpose of this study was to assess the influence of capsular closure on clinical outcome scores and satisfaction in patients who underwent hip arthroscopy surgery for femoroacetabular impingement (FAI) and labral tear. Data were prospectively collected and retrospectively analysed for hip arthroscopy surgeries with a minimum 2 years follow-up. Patients with developmental dysplasia of the hip, previous back or hip surgeries, and degenerative changes to this hip and secondary gains were excluded. Demographic data, intraoperative findings and patient-reported outcome scores were recorded, including the Modified Harris Hip Score (MHHS) and Hip Outcome Score (HOS). A total of 29 and 35 patients were included in the non-closure and closure groups, respectively. The mean follow-up time was over 3 years for both groups. The mean pre-operative and post-operative HOS scores and MHHS scores did not significantly differ between groups (pre-operative HOS: 65.6 and 66.3, P = 0.898; post-operative HOS: 85.4 and 87.2, P = 0.718; pre-operative MHHS: 63.2 and 58.4, P = 0.223; post-operative MHHS: 85.7 and 88.7, P = 0.510). Overall patient satisfaction did not differ significantly between groups (non-closure 86.3%, closure group 88.6%; P = 0.672). Capsular closure did not significantly influence satisfaction or clinical outcome scores in patients who underwent arthroscopic hip surgery for FAI or labral tear.

Chondral lesions in the hip: a review of relevant anatomy, imaging and treatment modalities

The diagnosis and treatment of chondral lesions in the hip is an ongoing challenge in orthopedics. Chondral lesions are common and several classification systems exist to classify them based on severity, location, radiographic parameters, and potential treatment options. When working up a patient with a potential hip chondral lesion, a complete history, thorough physical exam, and ancillary imaging are necessary. The physical exam is performed with the patient in standing, supine, prone, and lateral positions. Plain film radiographs are indicated as the first line of imaging; however, magnetic resonance arthrogram is currently the gold standard modality for the diagnosis of chondral lesions outside of diagnostic arthroscopy. Multiple treatment modalities to address chondral lesions in the hip exist and new treatment modalities continue to be developed. Currently, chondroplasty, microfracture, cartilage transplants (osteochondral autograft transfer, mosaicplasty, Osteochondral allograft transplantation) and incorporation of orthobiologics (Autologous chondrocyte implantation, Autologous matrix-induced chondrogenesis, Mononuclear concentrate in platelet-rich plasma) are some techniques that have been successfully applied to address chondral pathology in the hip. Further refinement of these modalities and research in novel techniques continues to advance a surgeon’s ability to address chondral lesions in the hip joint.

Graft choices for acetabular labral reconstruction

The acetabular labrum plays a key role in maintaining hip function and minimizing hip degeneration. Once thought to be a rare pathology, advances in imaging have led to an increase in the number of diagnosed labral tears. While still a relatively new field, labral reconstruction surgery is an option for tears that are irreparable or require revision after primary repair. Various autograft and allograft options exist when considering labral reconstruction. The first labral reconstruction surgery was described using the ligamentum teres capitis, and has since evolved, incorporating more graft sources and reconstructive techniques. The purpose of this review is to assess and describe the different graft sources and technique currently implemented by hip surgeons. Moreover, this review attempts to determine whether a single labral reconstructive graft type is superior to the others. Techniques using the Ligamentum teres capitis autograft, ITB autograft, gracilis autograft, quadriceps tendon autograft, capsular autograft, semitendinosus allograft, indirect head of the rectus femoris autograft, peroneus brevis tendon allograft and Tensor fascia lata allograft were found. Scoring was available on 5 out of the 9 graft types. The advantages and disadvantages of each graft source is described as a comparative tool. No single graft type has shown increased benefit in acetabular labral reconstruction. The lack of uniform outcome measurements hinders comparison of reported outcomes. Surgeons should make an informed decision based on their experience as well as the patient's history and needs when choosing which graft type would be best suited for their patients.

Acetabular labral reconstruction using the indirect head of the rectus femoris tendon significantly improves patient reported outcomes

PURPOSE AND HYPOTHESIS

The aim of this study was to evaluate outcomes after acetabular labral reconstruction using the indirect head of the rectus femoris tendon. The study hypothesis stated that arthroscopic acetabular labral reconstruction may improve patient reported outcomes in patients with labral tears that were not amenable to repair.

METHODS

Between 2009 and 2015, the senior author performed 31 acetabular labral reconstructions using the indirect head of the rectus femoris tendon. The graft is harvested through the same arthroscopic portals established for the procedure. The graft was gradually secured to the acetabular rim starting at its origin to the myotendinous junction, reestablishing the suction seal of the joint. Medical records and surgical reports were reviewed for demographic data, and outcome measures were assessed with pre- and postoperative modified Harris Hip Scores (mHHS).

RESULTS

Twenty-two patients with follow-up of more than 2 years were evaluated. Fourteen procedures were revision hip arthroscopy and 8 were primary labral reconstruction in 13 males and 9 females. The median age was 43 (range 22-68 years old). The median follow-up time was 36.2 months with a range from 24 to 72 months. The median preoperative mHHS was 67.1. Postoperatively, patients improved to a median mHHS of 97.8 (range 73.7-100) (p < 0.0001).

CONCLUSION

Acetabular labral reconstruction using the indirect head of the rectus femoris tendon is a minimally invasive surgical procedure. The technique was applicable in all patients in this study with good outcomes. This procedure is clinically relevant for patients with large labral tears not amendable to labral repair as it offers good results using a local allograft. The local allograft is clinically advantageous as there is no additional donor-site morbidity and no risk of disease transmission.

LEVEL OF EVIDENCE

IV.

Cerebrovascular accidents associated with hip fractures: morbidity and mortality-5-year survival

BACKGROUND

Hip fractures are associated with increased cerebrovascular accidents (CVAs) in the first postoperative year. Long-term follow-up for CVA and mortality after hip fracture is lacking. The purpose of this study was to identify risk factors for CVA and follow mortality in hip fractures in a cohort with greater than 2 years follow-up.

METHODS

We compared past medical history of patients with hip fractures to long-term survival and the occurrence of CVA. Past medical history, surgical intervention, CVA occurrence, and death were queried from the electronic medical recorder system. Level of significance was set at p < 0.05 with 95% confidence interval.

RESULTS

Two thousand one hundred ninety-five patients met inclusion criteria. Mean follow-up was 5 years. One hundred ten (5.01%) patients were diagnosed with post-fracture CVA. Forty-one patients had CVA in the first year and 55 patients had CVA between 1 to 5 years after surgery. Among the potential risk factors, hypertension (HTN), atrial fibrillation (AF), and diabetes mellitus (DM) had the highest odds ratio for CVA (OR = 1.885, p value = 0.005; OR = 1.79, p value = 0.012; OR = 1.66, p value = 0.012). The median survival time in patients with CVA was 51.12 ± 3.76 months compared to 59.60 ± 0.93 months in patients without CVA (p = 0.033).

CONCLUSIONS

HTN, AF, and DM are significant risk factors for the occurrence of CVA after hip fracture. The majority of CVAs occur between the first and fifth year postoperatively, and CVA is a negative prognostic factor for postoperative survival.

A novel non-invasive hip traction technique for hip arthroscopy in the below-knee amputation (BKA) patient

Prolonged sitting and mobilizing from a seated position are known to exacerbate the symptoms in patients with hip pathology. For patients who lack mobility and require extended periods of time in seated positions, such as amputees, the symptoms of femeroacetabular impingement can be debilitating and limit their ability to operate a wheelchair, use a prosthetic limb or complete activities of daily living. Hip arthroscopy surgery offers a minimally invasive technique to treat hip pathology but requires hip distraction to facilitate instrument maneuverability. Invasive methods of hip distraction have been previously described for use in amputees for hip arthroscopy. We herein describe a non-invasive surgical technique for hip distraction in the below-knee amputation patient.

The Long-Term Outcome After Varus Derotational Osteotomy for Legg-Calvé-Perthes Disease: A Mean Follow-up of 42 Years

BACKGROUND

Varus derotational osteotomy (VDRO) is one of the most common surgical treatments for Legg-Calvé-Perthes disease, yet its long-term results have not been fully assessed. We aimed to determine the long-term clinical and radiographic outcomes following VDRO.

METHODS

Forty patients (43 hips) who underwent VDRO for Legg-Calvé-Perthes disease at our institution from 1959 to 1983, and participated in a follow-up study completed 10 years earlier, were approached for the present study. Clinical examination and radiographs were evaluated. Hip status and well-being were assessed with the Harris hip score and the Short Form-36 (SF-36).

RESULTS

Thirty-five patients (37 hips) participated in the study. Information regarding the need for an arthroplasty was gathered on 4 additional hips from the previous study. The mean follow-up was 42.5 years (range, 32.4 to 56.5 years), with a mean patient age of 50.2 years (range, 35.9 to 67.8 years). In total, 7 patients (7 hips; 17% of 41 hips for which information was available, including 1 hip from the original cohort of 40 patients [43 hips]), underwent a total hip arthroplasty for hip pain. Excluding patients who had undergone an arthroplasty, the mean Harris hip and SF-36 scores were 79.8 points (range, 23.1 to 100 points) and 74.8 (range, 15.1 to 100), respectively. Twenty (64.5%) of the 31 hips that had not been replaced achieved a good or excellent Harris hip score (≥80 points). Sixteen (57.1%) of 28 hips with follow-up radiographs had no, or minimal, signs of osteoarthritis. The Stulberg classification was associated with the Harris hip score, the SF-36 score, hip pain, a Trendelenburg sign, coxa magna, and the Tönnis grade. In a multivariate analysis, the Stulberg classification was the only factor associated with fair or poor outcomes (a Harris hip score of <80 points). Patients with a Stulberg class-III or IV hip had significant deterioration with respect to the Harris hip score and Tönnis grade during the 10-year period since the last follow-up.

CONCLUSIONS

A long-term follow-up of patients who were operatively treated for Legg-Calvé-Perthes disease revealed that a low proportion underwent total hip arthroplasty and a relatively high proportion maintained good clinical and radiographic outcomes.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Hip arthroscopy for intra-capsular benign tumors: a case series

The purpose of this study is to demonstrate the assessment of intra-capsular femoral head and neck tumors, and to describe the arthroscopic surgical technique used to resect and fill the bone defects. Three cases of benign femoral head and neck lesions are presented. Two benign enchondromas and one benign osteochondroma were resected arthroscopically. Traction was used in one case. Modified Harris Hip Score improved in all three cases to scores of 95 or greater with an average improvement of 16 points with a minimum follow up of 15 months. Arthroscopic surgical resection of intra-capsular femoral hip lesions offers an effective alternative to open resection. This technique offered good outcomes in the limited cohort. We suggest that arthroscopic resection of intra-capsular femoral hip lesions be considered in relevant cases as an alternative to open resection.

[Carpal tunnel syndrome in pregnancy]

Pregnancy related carpal tunnel syndrome (PRCTS) is the most frequent mononeuropathy during pregnancy. The reported incidence of PRCTS varies widely and ranges from 0.8% to 70% depending on the diagnostic method and the physician. The etiology for PRCTS is related to hormonal fluctuations, fluid accumulation, glucose level fluctuations, median nerve hypersensitivity etc. The diagnosis of PRCS is the same as carpal tunnel syndrome (CTS) in the gereral population and includes a thorough history, typical symptoms and physical examination. Electrodiagnostic studies such as EMG are valuable tools for the ratification of the diagnosis of CTS in the general population. But in light of the fact that the EMG examination is painful and can cause discomfort to the patient, its routine use during pregnancy is controversial and is not required for determining the diagnosis. Generally, the syndrome tends to pass after birth, on the other hand, according to the literature, it might not pass in lactating women until they stop breastfeeding and even afterwards. Treatment of PRCS is mostly conservative, and if there is lack of improvement local intracarpal injection of a steroid is indicated. Intracarpal injections have demonstrated a significant decrease in symptoms and low recurrence in comparison to the general population, and do not put the fetus or his mother at risk. A surgical intervention is rarely indicated during pregnancy.

Expression pattern and secretion of human and chicken heparanase are determined by their signal peptide sequence

Cleavage of heparan sulfate (HS) proteoglycans affects the integrity and function of tissues and thereby fundamental phenomena, involving cell migration and response to changes in the extracellular microenvironment. The role of HS-degrading enzymes, commonly referred to as heparanases, in normal development has not been identified. The present study focuses on cloning, expression, and properties of a chicken heparanase and its distribution in the developing chicken embryo. We have identified a chicken EST, homologous to the recently cloned human heparanase, to clone and express a functional chicken heparanase, 60% homologous to the human enzyme. The full-length chicken heparanase cDNA encodes a 60-kDa proenzyme that is processed at the N terminus into a 45-kDa highly active enzyme. The most prominent difference between the chicken and human enzymes resides in the predicted signal peptide sequence, apparently accounting for the chicken heparanase being readily secreted and localized in close proximity to the cell surface. In contrast, the human enzyme is mostly intracellular, localized in perinuclear granules. Cells transfected with a chimeric construct composed of the chicken signal peptide preceding the human heparanase exhibited cell surface localization and secretion of heparanase, similar to cells transfected with the full-length chicken enzyme. We examined the distribution pattern of the heparanase enzyme in the developing chicken embryo. Both the chicken heparanase mRNA and protein were expressed, as early as 12 h post fertilization, in cells migrating from the epiblast and forming the hypoblast layer. Later on (72 h), the enzyme is preferentially expressed in cells of the developing vascular and nervous systems. Cloning and characterization of heparanase, the first and single functional vertebrate HS-degrading enzyme, may lead to identification of other glycosaminoglycan degrading enzymes, toward elucidation of their significance in normal and pathological processes.

Molecular properties and involvement of heparanase in cancer progression and normal development

Heparan sulfate proteoglycans (HSPGs) play a key role in the self-assembly, insolubility and barrier properties of basement membranes and extracellular matrices. Hence, cleavage of heparan sulfate (HS) affects the integrity and functional state of tissues and thereby fundamental normal and pathological phenomena involving cell migration and response to changes in the extracellular microenvironment. Here, we describe the molecular properties, expression and function of a human heparanase, degrading HS at specific intrachain sites. The enzyme is synthesized as a latent approximately 65 kDa protein that is processed at the N-terminus into a highly active approximately 50 kDa form. The heparanase mRNA and protein are preferentially expressed in metastatic cell lines and human tumor tissues. Overexpression of the heparanase cDNA in low-metastatic tumor cells conferred a high metastatic potential in experimental animals, resulting in an increased rate of mortality. The heparanase enzyme also releases ECM-resident angiogenic factors in vitro and its overexpression induces an angiogenic response in vivo. Heparanase may thus facilitate both tumor cell invasion and neovascularization, both critical steps in cancer progression. The enzyme is also involved in cell migration associated with inflammation and autoimmunity. The unexpected identification of a single predominant functional heparanase suggests that the enzyme is a promising target for drug development. In fact, treatment with heparanase inhibitors markedly reduces tumor growth, metastasis and autoimmune disorders in animal models. Studies are underway to elucidate the involvement of heparanase in normal processes such as implantation, embryonic development, morphogenesis, tissue repair, inflammation and HSPG turnover. Heparanase is the first functional mammalian HS-degrading enzyme that has been cloned, expressed and characterized. This may lead to identification and cloning of other glycosaminoglycan degrading enzymes, toward a better understanding of their involvement and significance in normal and pathological processes.

Mammalian heparanase as mediator of tumor metastasis and angiogenesis

Expression of heparan sulfate-degrading endoglycosidases, commonly referred to as heparanases, correlates with the metastatic potential of tumor cell lines, and treatment with heparanase inhibitors markedly reduces the incidence of metastasis in experimental animals. We purified a 50 kDa heparanase from human hepatoma and placenta and cloned a cDNA and gene encoding a protein of 543 amino acids. Only one heparanase sequence was identified, suggesting that this enzyme is the dominant endoglucuronidase in mammalian tissues. Expression of the cloned cDNA in insect and mammalian cells yielded 65 kDa and 50 kDa recombinant proteins. The 50 kDa enzyme represents an N-terminal processed enzyme that is at least 200-fold more active than the full-length 65 kDa form. Processing was demonstrated following incubation of the full-length recombinant enzyme with intact tumor cells. The heparanase mRNA and protein are preferentially expressed in metastatic cell lines and in specimens of human melanomas and carcinomas. In the colon, both the heparanase mRNA and protein are expressed already at the stage of tubulovillous adenoma, but not in the adjacent 'normal-looking' colon epithelium. Non-metastatic murine T lymphoma and melanoma cells transfected with the heparanase gene acquired a highly metastatic phenotype in vivo. Apart from its involvement in the egress of cells from the vasculature, heparanase is tightly involved in angiogenesis, both directly--by promoting invasion of endothelial cells (vascular sprouting), and indirectly--by releasing heparan sulfate-bound basic fibroblast growth factor, and generating HS degradation fragments that promote bFGF activity. The angiogenic potential of heparanase was demonstrated in vivo (Matrigel plug assay) by showing a three to fourfold increase in neovascularization induced by Eb T lymphoma cells following their transfection with the heparanase gene. The ability of heparanase to promote both tumor angiogenesis and metastasis makes it a promising target for cancer therapy.

Mammalian heparanase: gene cloning, expression and function in tumor progression and metastasis

Heparan sulfate proteoglycans interact with many extracellular matrix constituents, growth factors and enzymes. Degradation of heparan sulfate by endoglycosidic heparanase cleavage affects a variety of biological processes. We have purified a 50-kDa heparanase from human hepatoma and placenta, and now report cloning of the cDNA and gene encoding this enzyme. Expression of the cloned cDNA in insect and mammalian cells yielded 65-kDa and 50-kDa recombinant heparanase proteins. The 50-kDa enzyme represents an N-terminally processed enzyme, at least 100-fold more active than the 65-kDa form. The heparanase mRNA and protein are preferentially expressed in metastatic cell lines and specimens of human breast, colon and liver carcinomas. Low metastatic murine T-lymphoma and melanoma cells transfected with the heparanase cDNA acquired a highly metastatic phenotype in vivo, reflected by a massive liver and lung colonization. This represents the first cloned mammalian heparanase, to our knowledge, and provides direct evidence for its role in tumor metastasis. Cloning of the heparanase gene enables the development of specific molecular probes for early detection and treatment of cancer metastasis and autoimmune disorders.

The role of the supervisor in training social workers treating HIV infected persons in a hospital

The role of social workers working with HIV infected persons in hospitals is complex and laden with sources of professional stress, including those related to the hospital framework and environment and personal stress related to patients, their families, and the workers themselves. The paper identifies these factors of stress and discusses the functions of the supervision in avoiding or reducing them. The article is based on experience in Israel, but the analysis may be applicable elsewhere, as well.

Modulation of Mdm2 expression and p53-induced apoptosis in immortalized human ovarian granulosa cells

The activity of the tumor suppressor gene p53 is implicated in arrest of the cell cycle and the induction of apoptosis. The mdm2 oncogene is transcriptionally activated by p53, and the protein products of this gene can down-modulate biochemical activities and biological effects of p53 in a cell context-dependent manner. We have established highly steroidogenic human granulosa cell lines expressing the Ha-ras oncogene and a temperature sensitive (ts) mutant of p53 (p53val135) to test the involvement of p53-downstream genes in the modulation of apoptosis in these cells. We find that ras-transformed granulosa cells expressing p53val135 undergo apoptosis following a shift from 37 C to 32 C, a temperature at which p53val135 exerts its wild-type activity. Elevating the cellular content of cAMP at 32 C markedly enhances apoptosis. Basic fibroblast growth factor (bFGF) effectively blocks the p53/cAMP-induced apoptosis, but suppresses steroidogenesis. A naturally produced basement membrane-like extracellular matrix (ECM) containing immobilized bFGF exerts a similar antiapoptotic effect, but unlike soluble bFGF, it enhances steroidogenesis in these cells. While cAMP markedly suppresses the p53-induced Mdm2 expression, bFGF and ECM elevate Mdm2 expression 3-5-fold. These effects on Mdm2 expression are most pronounced 2-4 h after the shift to 32 C, before nuclear fragmentation is detected. Cells grown at 32 C in contact with ECM have a more developed actin cytoskeleton both in the absence and presence of cAMP stimulation, compared with cells grown on plastic dishes. We conclude that bFGF and components of the ECM can cross-talk with p53/cAMP-generated signals for apoptosis. These signals may, at least in part, be coordinated by the modulation of Mdm2 expression, which precedes the biochemical events characteristic of apoptosis. The multicomponent ECM also induced differentiation in these ras-transformed cells, while soluble bFGF inhibited differentiation, suggesting that ECM components other than bFGF stimulate differentiation. Organization of the actin cytoskeleton is likely to play an important role in the cross-talk between p53/cAMP- and bFGF/ECM-generated signals. Because the tumor suppressor gene p53 is implicated with apoptosis of primary granulosa cells and the ECM is involved in the prevention of this process, the newly established cell lines can serve as a useful model for apoptosis in highly luteinized granulosa cells.

Differential effect of components of the extracellular matrix on differentiation and apoptosis

BACKGROUND

Epithelial cells are closely associated with a basement membrane, but the intimate relationships that affect growth, differentiation and survival remain enigmatic. We have previously reported that granulosa cells adjacent to the basement membrane of the ovarian follicle have a higher degree of differentiation compared with cells located distal to the basement membrane. By contrast, granulosa cells distal to the basement membrane are the first to undergo apoptosis during follicular atresia. Moreover, growth of granulosa cells in vitro on a naturally produced basement-membrane-like extracellular matrix (ECM) enhances progesterone production and the cellular response to gonadotropic hormones by an undefined mechanism.

RESULTS

To investigate the effect of the ECM on granulosa cell differentiation and death, primary granulosa cells were cultured on ECMs that lacked or contained bFGF (basic fibroblast growth factor). These otherwise identical ECMs were deposited by HR9 mouse endodermal cells, which do not synthesize bFGF, or by HR9 cells transfected with the bFGF gene. Both ECMs provided protection against apoptosis in serum-free medium, but only the bFGF-containing ECM maintained expression of the steroidogenic P450scc enzyme system and the production of progesterone. Moreover, culturing the cells on this ECM enhanced the expression of the 30 kDa steroid acute regulatory protein which plays a key role in steroid hormone biosynthesis. Laminin, but not fibronectin, was able to replace the ECM in protecting the cells from apoptosis; but not in maintaining steroidogenesis, whereas bFGF was able to enhance steroidogenesis without protecting the cells against apoptosis. Cells cultured on both ECMs or laminin had a well-developed actin cytoskeleton compared with cells cultured on non-coated dishes, which underwent apoptosis.

CONCLUSIONS

Cellular responses to ECM are mediated by the combined action of macromolecular constituents and regulatory molecules, such as bFGF, that are sequestered and stored in the ECM. ECM or laminin protects against cell death by interacting with specific integrin receptors and maintaining a well-developed actin cytoskeleton. ECM-bound bFGF provides differentiation signals for granulosa cells, which are in intimate contact with the ECM. Thus, a clear distinction can be made between the survival activity and the differentiation stimulus exerted by the ECM on epithelial cells.

Sulfate moieties in the subendothelial extracellular matrix are involved in basic fibroblast growth factor sequestration, dimerization, and stimulation of cell proliferation

The growth promoting activity of the subendothelial extracellular matrix (ECM) is attributed to sequestration of basic fibroblast growth factor (bFGF) by heparan sulfate proteoglycans and its regulated release by heparin-like molecules and heparan sulfate (HS) degrading enzymes. HS is also involved in bFGF receptor binding and activation. The present study focuses on the growth promoting activity and bFGF binding capacity of sulfate-depleted ECM. Corneal endothelial cells (EC) maintained in the presence of chlorate, an inhibitor of phosphoadenosine phosphosulfate synthesis, produced ECM containing 10-15% of the sulfate normally present in ECM. Incorporation of sulfate into HS was reduced by more than 90%. Binding of 125I-bFGF to sulfate-depleted ECM was reduced by 50-60% and only about 10% of the ECM-bound bFGF was accessible to release by heparin. Incubation of 125I-bFGF on top of native ECM resulted in dimerization of the ECM-bound bFGF, but there was a markedly reduced binding and dimerization of bFGF on sulfate-depleted ECM. ECM produced in the presence of chlorate contained a nearly 10-fold less endogenous bFGF as compared to native ECM and exerted little or no mitogenic activity toward vascular EC and 3T3 fibroblasts. In other studies, we investigated the interaction between chlorate-treated vascular EC and either native or sulfate-depleted ECM. Exogenous heparin stimulated the proliferation of chlorate-treated EC seeded on native ECM, suggesting its interaction with ECM-bound bFGF and subsequent presentation to high affinity cell surface receptors. On the other hand, heparin had no effect on chlorate-treated cells seeded in contact with sulfate-depleted ECM or regular tissue culture plastic. Altogether, the present experiments indicate that heparan sulfate proteoglycans associated with the cell surface and ECM act in concert to regulate the bioavailability and growth promoting activity of bFGF. While HS in the subendothelial ECM functions primarily in sequestration of bFGF in the vicinity of responsive cells, HS on cell surfaces is playing a more active role in displacing the ECM-bound bFGF and its subsequent presentation to high affinity signal transducing receptors.

Basic fibroblast growth factor is an extracellular matrix component required for supporting the proliferation of vascular endothelial cells and the differentiation of PC12 cells

Vascular endothelial cells (ECs) seeded sparsely on extracellular matrix (ECM) will proliferate in the absence of exogenous basic fibroblast growth factor (bFGF). This ECM will also stimulate neurite outgrowth in PC12 cells in the absence of exogenous growth factors. We have previously shown that bFGF is found in subendothelial ECM (Vlodavsky, I., J. Folkman, R. Sullivan, R. Fridman, R. Ishai-Michaeli, J. Sasse, and M. Klagsburn. 1987. Proc. Natl. Acad. Sci. USA. 84:2292-2296) and in basement membranes (Folkman, J., M. Klagsburn, J. Sasse, M. Wadzinski, D. Ingber, and I. Vlodavsky. 1988. Am. J. Pathol. 130:393-400). The actual requirement of ECM-associated bFGF for the growth of ECs and differentiation of PC12 cells was shown in two ways. First, polyclonal anti-bFGF antibodies added to subendothelial ECM inhibited both EC proliferation and PC12 neurite outgrowth. Secondly, PF-HR-9 cells, which do not synthesize bFGF and which produce an ECM not permissive for EC proliferation and PC12 neurite outgrowth, were transfected with bFGF cDNA. PF-HR-9 cells transfected with bFGF, but not with the dominant selectable marker SV2-neomycin, were found to express bFGF and to produce an ECM which did support both EC proliferation and PC12 differentiation. The ECM-mediated stimulatory effects were inhibited by anti-bFGF antibodies but not by anti-nerve growth factor antibodies or nonimmune rabbit IgG. These results indicate that bFGF associated with ECM is a required ECM component for ECM-mediated cell proliferation and differentiation.

Striated muscle fibers differentiate in primary cultures of adult anterior pituitary cells

Anterior pituitary cells from adult male rats were cultured on a natural extracellular matrix (ECM). From the 5th day, spindle-shaped cells, fusing to form elongated fibers, were observed among the epithelial cells. These fibers later increased in size and number and were identified as striated muscle fibers, based on their multi-nucleation, cross-striation and rhythmic contraction. Striated muscle development was further validated by the appearance of cholinergic-nicotinic receptors, as demonstrated by the binding of 125I-alpha bungarotoxin (a-Btx). The effect of various supplements added to the cultures on a-Btx binding was used as a measure of muscle cell differentiation. ECM and serum were essential for myotube formation. Insulin (or IGF-I) and cortisol synergistically caused a 20-fold increase in myogenesis. FGF and EGF were effective only in the presence of insulin and cortisol. The data suggest that: (a) cells, derived from adult pituitary, differentiate, in primary culture, into striated muscle fibers; (b) the induction of this differentiation is multi-factorial; ECM, serum, insulin and glucocorticoids facilitate this myogenesis.

Serum reduces the TSH content in rat pituitary cells in culture

Euthyroid rat pituitary cells were plated on a natural extracellular matrix (ECM) and cultured in either a medium supplemented with hormones and growth factors (SM) or in an unsupplemented medium (USM). Hormone supplementation resulted in a marked increase in the number of cells and in a less pronounced increase in the TSH content. Addition of 10% dehormonized serum (DHS) to the medium caused a further increase in the cell number as well as a significant elevation in the GH content but, surprisingly, it caused also a dramatic decrease in the TSH content. Time course experiments revealed that the serum doubled the rate of suppression of the TSH. DHS prepared from rat serum was as effective as that prepared from foetal calf serum and heat-inactivation of the serum did not change its suppressive effect on the production of TSH. This effect was confined to the serum fraction which was precipitable with 45% ammonium sulphate but did not bind to Con-A. It is suggested that a high molecular weight protein fraction of serum reduces the number of thyrotrophs in the culture and/or decreases the rate of TSH production by these cells.

Thyrotrophin and growth hormone secretion and cell morphology in hypothyroid pituitary cells cultured on a natural extracellular matrix

Hypothyroid rat pituitary cells were cultured on an extracellular matrix (ECM) produced by corneal endothelial cells. ECM markedly affected the following parameters. 1) Cell attachment, spreading and proliferation were improved, resulting in a more rapid formation of confluent cell monolayers. 2) In the presence of ECM the production of both thyrotrophin (TSH) and growth hormone (GH) was larger than in its absence. Immunofluorescence studies revealed that 20% of the cells in these monolayers were thyrotrophs; consequently, TSH content was higher while GH level was lower than in control cultures of euthyroid pituitaries. These data suggest that the in vivo physiological differences are maintained by the conditions of the culture. 3) ECM enabled the response of both the somatotrophs and the thyrotrophs to thyrotrophin releasing hormone (TRH) and the cells remained responsive for at least 10 days. Maximal stimulation (1.3- to 6-fold) was obtained with 14 nM of TRH. In the absence of ECM the cells failed to respond to TRH. 4) Cell morphology was examined by scanning electron microscopy (SEM). Cells grown on ECM were characteristically epithelial, whereas those cultured on plastic plates had a fibroblast-like appearance. Four types of cells were identified in the epithelial cell monolayers by the appearance of their surface. TRH induced a 2-fold increase in the number of cells covered with microvilli and a corresponding decrease in the number of smooth surfaced cells. This suggests that hormone secretion is associated with the formation of microvilli.

The effect of radiation on prostacyclin (PGI2) production by cultured endothelial cells

The effect of ionizing irradiation on the synthesis of prostacyclin (PGI2) by cultured bovine aortic endothelial cells was determined. PGI2 was measured in the culture medium by a radioimmunoassay for 6-Keto PGF1 alpha. Two phenomena were observed following irradiation: a) Cells which suffered an immediate radiation damage (1000-5000 rads) released high quantities of PGI2 to the culture medium. This was due to a de novo synthesis of PGI2 stimulated by radiation induced cellular damage, since pretreatment with aspirin of the endothelial cell monolayers resulted in a marked inhibition of PGI2 release following irradiation. b) Metabolically active cells which remained confluent and firmly attached to the culture dish following single, low and intermediate doses (200-1200 rads) radiation, exhibited a marked decrease in their capacity to synthesize PGI2 upon exposure to various stimuli of the arachidonic acid cascade (arachidonic acid, melittin, ionophore A23187 and PGH2). Similar results were observed with cells treated with fractionated radiation. The quantities of PGI2 produced by the endothelial cells decreased as a function of the dose of radiation and time interval between irradiation and subsequent stimulation. Radiation had a minimal effect on the nonthrombogenic properties of the endothelial cells, as evidenced by the small increase in platelet adherence to the endothelial cells. The effect of radiation on PGI2 production by the vascular endothelium may be relevant to the development of radiation induced capillary occlusions, and the enhancement of atherosclerotic lesions in large vessels.

Cultured endothelial cells increase their capacity to synthesize prostacyclin following the formation of a contact inhibited cell monolayer

The synthesis of the prostaglandins (PG), prostacyclin (PGI2), PGE2, and thromboxane A2 (TXA2), has been investigated in actively growing and contact-inhibited bovine aortic endothelial cell cultures. Cells were stimulated to synthesize prostaglandins by exposure to exogenous arachidonic acid or to the endoperoxide PGH2 and by the liberation of endogenous arachidonic acid from cellular lipids with melittin or ionophore A23187. Increased capacity of the cells to synthesize PGI2 and PGE2 was observed as a function of time in culture, regardless of the type of stimulation. TXA2 production increased with time only upon stimulation of the cells with ionophore A23187. This increased PG synthetic capacity was independent of cell density since it was mainly observed in confluent, nondividing endothelial cell cultures. The fact that increased PGI2 production in confluent cells was also observed with PGH2, a direct stimulator of PGI2 synthetase, implies that this process is independent of the arachidonate concentration within the cells or in the culture medium. This increased capacity is likely to reflect an increased activity of the PG synthetase system associated with the formation of a contact inhibited endothelial cell monolayer. A similar time-dependent increase in the PGI2 production capacity was also observed during growth of cultured bovine corneal endothelial cells.