Light microscopic histology of quadriceps tendon ruptures

Smaller Gap Formation With Suture Anchor Fixation Than Traditional Transpatellar Sutures in Patella and Quadriceps Tendon Rupture: A Systematic Review

PURPOSE

The purpose of this study is to compare the biomechanical properties between traditional transosseous tunnel and suture anchor technique repair for extensor mechanism ruptures and assess for differences in the mechanism of failure of both techniques.

METHODS

A multi-database search (PubMed, EMBASE, and Medline) was performed according to PRISMA guidelines on November 14, 2021. All articles comparing biomechanical properties of transpatellar and suture anchor technique for extensor mechanism ruptures were included. Abstracts, reviews, case reports, studies without biomechanical analysis, conference proceedings, and non-English language studies were excluded. Outcomes pursued included gap formation, load to failure, and mechanism of failure. Relevant data from studies meeting inclusion criteria were extracted and analyzed. Study methodology was assessed using the Methodological Index for Non-Randomized Studies score.

RESULTS

A total of 212 knees were biomechanically assessed, including 98 patella and 114 quadricep tendon ruptures. Five patellar tendon studies were included, and all of them reported significantly smaller gap formation in suture anchor group. Gap formation for suture anchors ranged from .9 mm to 4.1 mm, while that of transpatellar group ranged from 2.9 mm to 10.3 mm. One study reported a significantly higher load to failure in the suture anchor group, while the remaining four studies reported no significant difference. Load to failure for suture anchor ranged from 259 N to 779 N, while that of the transpatellar group ranged from 287 N to 763 N. The most common mechanism of failure was anchor pullout in suture anchor and knot failure in the transpatellar group. Five quadriceps tendon studies were included, and three studies reported statistically significant smaller gap formation in the suture anchor group. Gap formation for suture anchor ranged from 1.5 mm to 5.0 mm, while that of transpatellar group ranged from 3.1 mm to 33.3 mm. Two studies reported a significantly higher load to failure in the suture anchor group, while one study reported a higher load to failure in the transpatellar repair group. Load to failure for suture anchor ranged from 286 N to 740 N, while that of transpatellar group ranged from 251 N to 691 N. The most common mechanism of failure was suture failure in the suture anchor and knot failure in the transpatellar group.

CONCLUSION

Suture anchor fixation displays a better biomechanical profile than traditional transpatellar techniques in terms of smaller gap formations in the repair of both patella and quadriceps tendon injuries. Anchor pullout in suture anchor fixation was present mainly with the use of titanium anchors.

CLINICAL RELEVANCE

These findings above may result in better retention of tendon approximation in patella and quadriceps tendon fixation postoperatively, which may result in earlier recovery. Further randomized controlled clinical trials to compare these techniques are required.

Differentiation Ability of Tendon-Derived Stem Cells and Histological Characteristics of Rotator Cuff Remnant on the Greater Tuberosity Degenerated With Age and Chronicity

PURPOSE

To explore and measure the presence and activity of tendon-derived stem cells (TDSCs), as well as histological changes of rotator cuff remnant by age and chronicity of the rotator cuff tear (RCT).

METHODS

154 patients with a full-thickness tear of supraspinatus and/or infraspinatus tendon were included. 52 qualified remnants of the greater tuberosity were captured through arthroscopy. TDSCs in the remnants were isolated for proliferation ability, basal gene expression, and trilineage differentiation detection. Histological characteristics were evaluated by observation of staining under a light microscope and transmission electron microscopy (TEM). To observe the effect of age, samples were divided into two groups: young (＜60 years old) and old (≥60 years old). For chronicity comparison, samples were divided into three groups: acute group (＜3 months), intermediate group (3-12 months), and chronic group (≥12 months).

RESULTS

Between age groups, the remnants in older patients were found to have lower TDSC proliferation ability (cell counting kit-8 results, old: .5325 ± .050, young: .6623 ± .196; P = .008) and basal expression of aggrecan (.630 ± .239; P = .002) and TGF-β1 (transforming growth factor-β1, .589 ± .326, P = .008), weaker ability of chondrogenic differentiation. Furthermore, the remnant tendons in chronic group was found to have weaker adipogenic and chondrogenic differentiation ability of TDSCs, lower tendon degenerative score (acute: 3.57 ± 1.902, intermediate: 5.94 ± 2.313, chronic: 6.86 ± 2.193; P = .023), increased type III collagen region ratio in insertion area (acute: 86.10% ± 8.29%, intermediate: 94.06% ± 5.36%, chronic: 98.90% ± .49%; P = .023), and larger fibril diameters.

CONCLUSION

Differentiation ability of TDSCs derived from the rotator cuff remnant was reduced with age and chronicity. Histological degeneration of remnant tendon deteriorated with chronicity. Remnant in the greater tuberosity was still alive, but those in young or acute injury patients were more active after full-thickness RCT.

CLINICAL RELEVANCE

TDSCs exist in rotator cuff remnant on the greater tuberosity and have multilineage differentiation ability. But the remnant degenerated with age and chronicity.

Failed Surgery for Patellar Tendinopathy in Athletes: Midterm Results of Further Surgical Management

Background:

Tendon injuries are commonly seen in sports medicine practice. Many elite players involved in high-impact activities develop patellar tendinopathy (PT) symptoms. Of them, a small percentage will develop refractory PT and need to undergo surgery. In some of these patients, surgery does not resolve these symptoms.

Purpose:

To report the clinical results in a cohort of athletes who underwent further surgery after failure of primary surgery for PT.

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 22 athletes who had undergone revision surgery for failed surgical management of PT were enrolled in the present study. Symptom severity was assessed through the Victorian Institute of Sport Assessment Scale for Patellar Tendinopathy (VISA-P) upon admission and at the final follow-up. Time to return to training, time to return to competition, and complications were also recorded.

Results:

The mean age of the athletes was 25.4 years, and the mean symptom duration from the index intervention was 15.3 months. At a mean follow-up of 30.0 ± 4.9 months, the VISA-P score improved 27.8 points (P < .0001). The patients returned to training within a mean of 9.2 months. Fifteen patients (68.2%) returned to competition within a mean of 11.6 months. Of these 15 patients, a further 2 had decreased their performance, and 2 more had abandoned sports participation by the final follow-up. The overall rate of complications was 18.2%. One patient (4.5%) had a further revision procedure.

Conclusion:

Revision surgery was feasible and effective in patients in whom PT symptoms persisted after previous surgery for PT, achieving a statistically significant and clinically relevant improvement of the VISA-P score as well as an acceptable rate of return to sport at a follow-up of 30 months.

The pathological features of hip abductor tendon tears - a cadaveric study

Background

The hip abductors are crucial in maintaining pelvic stability. Tears in these tendons are common and often debilitating. There is uncertainty regarding both the histological and macroscopic features of hip abductor tears. This study aims to clarify both the macroscopic and microscopic features of the tendon and enthesis in hip abductor tendon tears.

Methods

Thirty-six cadavers with an average age of 81 were dissected, and the hip abductor mechanisms removed en-bloc. The presence, location and size of the tears were recorded and analysed. The samples were processed into histological blocks and viewed using both transmitted and polarised light. Tendon histology was graded using the modified Movin’s score in three sections (deep, middle and superficial layers) and the enthesis graded separately using 5-point criteria. Analysis of variance was used to confirm histological features associated with tears.

Results

Tears were found in 24 of 36 samples (67%). The most common finding was an isolated tear in the gluteus minimus (46%), followed by concurrent gluteus medius and gluteus minimus tears (33%). Histology revealed significantly more degeneration in both the tendon (p = 0.0005) and enthesis (p = 0.0011) when tears were present. Furthermore, these changes were concentrated in the deeper layers of the tendon (p = 0.0002) and enthesis (p = 0.003).

Conclusion

This study demonstrated degeneration as the primary pathology underlying hip abductor tendon tears. Degenerative changes occur in both the tendon and enthesis, with the deeper layers predominantly affected. These findings are important for guiding surgical repair techniques and to aid the development of novel materials and biologics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-020-03784-3.

Management of Achilles and patellar tendinopathy: what we know, what we can do

Tendinopathies are challenging conditions frequent in athletes and in middle-aged overweight patients with no history of increased physical activity. The term “tendinopathy” refers to a clinical condition characterised by pain, swelling, and functional limitations of tendons and nearby structures, the effect of chronic failure of healing response. Tendinopathies give rise to significant morbidity, and, at present, only limited scientifically proven management modalities exist. Achilles and patellar tendons are among the most vulnerable tendons, and among the most frequent lower extremity overuse injuries. Achilles and patellar tendinopathies can be managed primarily conservatively, obtaining good results and clinical outcomes, but, when this approach fails, surgery should be considered. Several surgical procedures have been described for both conditions, and, if performed well, they lead to a relatively high rate of success with few complications. The purpose of this narrative review is to critically examine the recent available scientific literature to provide evidence-based opinions on these two common and troublesome conditions.

Optical Microscopy and Electron Microscopy for the Morphological Evaluation of Tendons: A Mini Review

The morphological characteristics of tendons have been thoroughly evaluated via microscopy. Optical microscopy and electron microscopy are the most commonly used techniques for tendon tissue observation. According to the principles of both microscopy types, preparation and evaluation methods vary. Simple optical microscopy is commonly used in the observation of cells and extracellular matrix, and many stains, including hematoxylin–eosin, Van Gieson, Prussian blue, Alcian blue, and toluidine blue, are used for evaluating cells, collagen fiber arrangement, and noncollagenous proteins. Histological scoring systems have been used in many studies for semi‐quantification. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are the most commonly used electron microscopy types, and special consideration is needed for the fixation and embedding protocols. Glutaraldehyde followed by osmium is most commonly used in the chemical fixation of tendon tissue, followed by epoxy resin embedment. Longitudinal sections captured in SEM images show the arrangement of collagen fibrils and the cells and lipid drops among them, while cross sections captured in TEM images show the diameter and distribution of collagen fibrils. SEM and TEM are used together for comprehensive evaluations. This mini review is focused on the preparation methodology and related evaluation indexes for the morphological evaluation of tendons.

Atraumatic acute bilateral quadriceps tendon rupture in a patient with bilateral patella spurs. A case report and review of literature

BACKGROUND AND AIM OF THE WORK

the spontaneous and simultaneous rupture of both quadriceps tendons is uncommon and has rarely been reported in medical literature. The current case involves a 62-years old man with bilateral atraumatic complete quadriceps tendon rupture. Aim of this study is to provide a systematic review of this case and a literature review of similar cases. Methods: we reviewed and analyzed this patient's records. Initial x rays of both knees showed a bilateral patellar spur. Real time ultrasonography scan of both knees showed a complete tear of quadriceps. The repair has consisted on end to end Krackow sutures associated with bone suture to the proximal pole of the patella using patellar drill holes. We also researched the literature for bilateral simultaneous rupture of the quadriceps tendon. Results: The patient suffered only from seasonal asthma (receiving only inhaled corticosteroids) and he was overweight (BMI: 33,5), he did not do any type of sport, he was a biker. The patient was able to walk after 3 weeks with both knee cast. The patients had a 120° pain free range of motion in both knees 4 months after surgery. Conclusion: Simultaneous bilateral quadriceps tendon rupture is really very rare and these are generally reported as case presentation in the literature. This injury usually presents in middle aged people with a history of chronic illness. The general recommendation is to perform surgical intervention within 48-72 hours after injury.

The increasing incidence of surgically treated quadriceps tendon ruptures

PURPOSE

Due to increased life expectancy and a more active life style of the older people, we hypothesised that the incidence of quadriceps tendon rupture (QTR) is higher than previously reported. The objective of this nationwide population-based study was to investigate the annual incidence of QTR in patients who underwent operative treatment in Finland between 1997 and 2014.

METHODS

The Finnish National Hospital Discharge Register was searched for all adult patients who had undergone surgical treatment for QTR during the study period. Population-based annual incidence and incidence trends for surgically treated QTR were calculated.

RESULTS

During the study period, 1343 QTR surgeries were performed. Of these, 90% were performed on male patients. The incidence of QTR increased by 411% from 0.55 to 2.82 per 100,000 person-years from 1997 to 2014. The average yearly increase in the number of surgeries was 9.0%. In male patients, the incidence of QTR increased by 490% and in female patients by 121%. The mean age of the male patients increased during the study period from 50 to 59 years.

CONCLUSIONS

Based on the data from the Finnish National Hospital Discharge Register, the annual incidence of QTR increased by over 400% during the 18-year study period. The average age of the patients also increased. Because QTR is only very rarely treated without surgery, the results of our study can be considered to be a reliable estimate of the increase in the incidence of this condition. There is an urgent need to establish the risk factors associated with QTR and to also establish the optimal surgical technique.

LEVEL OF EVIDENCE

IV.

More histologic and ultrastructural degenerative signs in the subscapularis tendon and the joint capsule in male patients with shoulder impingement

PURPOSE

The purpose of the present study was to analyze biopsy samples from the subscapularis tendon and from the joint capsule from male patients with shoulder impingement syndrome (SAIS) and compare them with samples from male patients with post-traumatic recurrent shoulder instability. The hypothesis of the study was that patients with SAIS would have more histologic and ultrastructural degenerative changes in their subscapularis tendon and joint capsule than patients with post-traumatic recurrent shoulder instability.

METHODS

Male patients scheduled for surgery, with either subacromial decompression or Bankart reconstruction, were included. Four biopsies from each patient were obtained from the capsule and four from the subscapularis tendon during arthroscopic surgery. The histologic characteristics and the presence of glycosaminoglycans were assessed using the light microscope, and the ultrastructure was assessed using a transmission electron microscope.

RESULTS

Eight patients, median age 53 (45-74) years (p < 0.0001), were included in the impingement group, and 12 patients, median age 27 (22-48) years, were included in the instability group. The histologic assessment revealed significantly higher cellularity and total degeneration score in the capsule (p = 0.016 and p = 0.014 respectively) in patients with subacromial impingement compared with the instability patients. The corresponding finding was not made for the subscapularis tendon. The ultrastructural evaluation revealed that the instability patients had more fibrils with a large diameter (indicating less degeneration) in both the subscapularis tendon and the capsule compared with the impingement patients (p < 0.0001).

CONCLUSION

Male patients with subacromial impingement have more histologic and ultrastructural degenerative changes in their shoulder compared with patients with post-traumatic recurrent shoulder instability.

CLINICAL RELEVANCE

It appears that in patients with subacromial impingement, the whole shoulder joint is affected and not only the subacromial space. It is the opinion of the authors that intra-articular therapeutic injections could be tried more often in these patients.

LEVEL OF EVIDENCE

III.

Effects of boric acid on the healing of Achilles tendons of rats

PURPOSE

Tendinous lesions are among the most frequent pathologies encountered in sportsmen. The objectives of new treatments are to improve the healing process and reduce the recovery time. Boron plays an important role in the wound repair process by increasing components of extracellular matrix and angiogenesis. This animal study aimed to investigate the effect of boric acid on healing of the Achilles tendon.

METHODS

The right Achilles tendons of 40 rats were completely sectioned, and the rats were randomly divided into five groups. Each group consisted of eight rats. Groups 1 and 2 were oral boric acid groups with the doses of 4 and 8 mg/kg/day boric acid, respectively. Group 3 was the local boric acid group (8 mg/kg boric acid intratendinous injection). Group 4 was administered both oral and local boric acid (8 mg/kg/day orally and 8 mg/kg boric acid intratendinous injection), and group 5 was the control group with no boric acid application. At the end of the fourth week, all the rats were killed and histopathological examination of the Achilles tendon repair site was made.

RESULTS

Histopathological examination of the tissue sections revealed more properly oriented collagen fibres, more normal cellular distribution of tenocytes and more properly organized vascular bundles in group 1 and group 2, which were the groups administered oral boric acid. Pathological sum scores of groups 1 and 2 were less than those of the other groups, and the differences between the oral boric acid groups (group 1 and group 2) and the other three groups (groups 3, 4 and 5) were statistically significant (p = 0.001).

CONCLUSION

As boric acid is safe and toxicity even after very high doses is unusual, oral boric acid may be used as an agent to improve the healing process of tendon injuries. However, biomechanical tests should also be performed to show the effect of boric acid on strength and endurance of the tendon before it can be used in clinical practice.

Outcomes after quadriceps tendon repair in patients over 80 years of age

BACKGROUND

Quadriceps tendon (QT) ruptures are uncommon and mostly occur in those who are 50-60 years of age. Timely surgical repair can result in a good functional outcome, however, little is known about the outcome in the older patient.

METHODS

A retrospective review of all QT ruptures between 2009 and 2014 was conducted. Patients over the age of 80 were included. Those with penetrating trauma or partial ruptures were excluded. A chart review was undertaken to gather demographic and operative details. The patients were contacted by phone or by mail to have Lysholm and Rougraff scores completed.

RESULTS

Of the 32 QT ruptures identified, 6 (19%) patients were eligible for inclusion in our study. They were predominantly (83%) males with a mean age of 81.38 years. The mean follow up was 54 months. The mean Lysholm score at last follow up was 84.8/100, which falls within the range of a good outcome. The mean Rougraff score was 21.3/25, which is an excellent outcome. All patients felt they were close to their premorbid level of mobility.

CONCLUSION

Good outcomes can be expected with QT repair in older patients, resulting in restoration of the pre-injury level of mobility. Level of evidence: Level V case series.

Prospective multicentre study of the clinical and functional outcomes following quadriceps tendon repair with suture anchors

INTRODUCTION

Quadriceps tendon avulsions are typically treated by reattaching the tendon through bone tunnels, with or without tendon or hardware augmentation. The operated knee joint can be moved right away; however, tendon grafting or tension banding will be required to protect the repair, and the hardware must be removed later on. The goal of this study was to evaluate the clinical and functional outcomes when suture anchors are used to reattached torn quadriceps tendon, and also to assess tendon healing using MRI.

MATERIALS AND METHODS

Thirteen consecutive patients with avulsed quadriceps tendons were operated and then followed prospectively. The surgical technique consisted of tendon reattachment using at least three anchors, in addition to intratendinous weaving of the sutures. Weight bearing was allowed while using a splint. Rehabilitation was initiated immediately after surgery according to a set protocol.

RESULTS

Eleven patients were followed for a mean of 14.7 months. Two retears occurred in patients who did not wear the splint. Eighty-two per cent of patients were satisfied or very satisfied with the outcome. The mean knee flexion was 124.5°. All patients were able to return to their pre-injury activity levels. The mean time for clinical and functional recovery was 3 months. MRI performed 6 months after the surgical repair revealed good tendon healing.

DISCUSSION

This was the first prospective study performed on quadriceps avulsion patients undergoing suture anchor repair. Prior clinical case reports have shown that this method leads to predictable clinical and functional results. Our results were comparable to those in published cases.

CONCLUSION

The procedure is simpler when only suture anchors are used. Tendon healing was observed on MRI in all cases. This simple, reproducible technique is free of the drawbacks associated with the typical repair augmentation.

Suture anchor repair yields better biomechanical properties than transosseous sutures in ruptured quadriceps tendons

PURPOSE

This human cadaveric study compares the biomechanical properties of quadriceps tendon repair with suture anchors and the commonly applied transosseous sutures. The hypothesis was that suture anchors provide at least equal results concerning gap formation and ultimate failure load compared with transosseous suture repair.

METHODS

Thirty human cadaveric knees underwent tenotomy followed by repair with either 5.5-mm-double-loaded suture anchors [titanium (TA) vs. resorbable hydroxyapatite (HA)] or transpatellar suture tunnels using No. 2 Ultrabraid™ and the Krackow whipstitch. Biomechanical analysis included pretensioning the constructs with 20 N for 30 s and then cyclic loading of 250 cycles between 20 and 100 N at 1 Hz in a servohydraulic testing machine with measurement of elongation. Ultimate failure load analysis and failure mode analysis were performed subsequently.

RESULTS

Tendon repairs with suture anchors yielded significantly less gap formation during cyclic loading (20th-250th cycle: TA 1.9 ± 0.1, HA 1.5 ± 0.5, TS 33.3 ± 1.9 mm, p < 0.05) and resisted significantly higher ultimate failure loads (TA 740 ± 204 N, HA 572 ± 67 N, TS 338 ± 60 N, p < 0.05) compared with transosseous sutures. Common failure mode was pull-out of the eyelet within the suture anchor in the HA group and rupture of the suture in the TA and TS group.

CONCLUSION

Quadriceps tendon repair with suture anchors yields significantly better biomechanical results than the commonly applied transosseous sutures in this human cadaveric study. These biomechanical findings may change the future clinical treatment for quadriceps tendon ruptures. Randomised controlled clinical trials are desirable for the future.

LEVEL OF EVIDENCE

Not applicable, controlled laboratory human cadaveric study.

Structural and biomechanical changes in the Achilles tendon after chronic treatment with statins

Cases of tendinopathy and tendon ruptures have been reported as side effects associated with statin therapy. This work assessed possible changes in the structural and biomechanical properties of the tendons after chronic treatment with statins. Wistar rats were divided into the following groups: treated with atorvastatin (A-20 and A-80), simvastatin (S-20 and S-80) and the group that received no treatment (C). The doses of statins were calculated using allometric scaling, based on the doses of 80 mg/day and 20 mg/day recommended for humans. The morphological aspect of the tendons in A-20, S-20 and S-80 presented signals consistent with degeneration. Both the groups A-80 and S-80 showed a less pronounced metachromasia in the compression region of the tendons. Measurements of birefringence showed that A-20, A-80 and S-80 groups had a lower degree of organization of the collagen fibers. In all of the groups treated with statins, the thickness of the epitenon was thinner when compared to the C group. In the biomechanical tests the tendons of the groups A-20, A-80 and S-20 were less resistant to rupture. Therefore, statins affected the organization of the collagen fibers and decreased the biomechanical strength of the tendons, making them more predisposed to ruptures.

Release of the medial head of the gastrocnemius for Achilles tendinopathy in sedentary patients: a retrospective study

PURPOSE

Our aim was to ascertain whether releasing the medial head of he gastrocnemius improves clinical and functional outcomes of sedentary patients with long-standing tendinopathy of the main body of the Achilles tendon and allows return to daily activities.

METHODS

Eighteen patients (seven men, 11 women) underwent release of the gastrocnemius medial head to manage chronic unilateral Achilles tendinopathy. Pre- and postoperatively, each patient completed the Victorian Institute of Sports Assessment-Achilles tendon (VISA-A) questionnaire. The maximum calf circumference and isometric plantar flexion strength of the gastrocsoleus complex were measured in both the affected and the contralateral leg. Function was scored using the 4-point Boyden scale at the last assessment.

RESULTS

At the last appointment, at an average follow-up of 54 months, maximum calf circumference and strength of the operated leg were not significantly different than pre-operatively and were significantly lower than the contralateral leg. All patients could satisfactorily perform the same work and daily activities as before symptom onset. At the last follow-up, the average VISA-A score was improved from a preoperative average value of 52.3 to 75 (range 51-94) (p < .001).

CONCLUSIONS

This approach to managing isolated Achiles tendinopathy is safe, effective, low cost and allows safe return to preinjury daily activities.

Surgery for unilateral and bilateral patellar tendinopathy: a seven year comparative study

PURPOSE

Open surgery for patellar tendinopathy allows patients with unilateral and bilateral tendinopathy to return to high levels of physical activity.

MATERIALS

Two groups of 23 athletes each underwent open surgical exploration for management of patellar tendinopathy. One group suffered from unilateral patellar tendinopathy (unilateral group), and the other group had bilateral (bilateral group) patellar tendinopathy. Maximum voluntary isometric contraction and anthropometric measures were assessed pre-operatively and at an average follow-up of seven years. The Victorian Institute of Sport Assessment (VISA)-P scoring system was also administered; functional outcomes were classified from excellent to poor according to a modification of Kelly's criteria.

RESULTS

At the final follow-up, in both groups, VISA-P scores were significantly improved compared with preoperative values, with no intergroup differences. Clinical results were excellent or good in 21 patients in the unilateral and 19 in the bilateral group. Twenty of 23 patients in the unilateral group and 17 of 23 in the bilateral group were still active in sports (p = 0.2). In the unilateral group, at the last follow-up, thigh volume and strength were significantly improved compared with baseline, with significant difference between operated and nonoperated limbs. In the bilateral group, there were no significant differences in thigh volume and strength between the dominant and nondominant limbs both before and after the index procedure.

CONCLUSIONS

This procedure is not technically demanding and provides a high rate of good and excellent outcomes in the long term.

[Molecular repair mechanisms using the Intratissue Percutaneous Electrolysis technique in patellar tendonitis]

OBJECTIVE

To investigate the molecular mechanisms of tissue response after treatment with the Intratissue Percutaneous Electrolysis (EPI(®)) technique in collagenase-induced tendinopathy in Sprague-Dawley rats.

METHODS

Tendinopathy was induced by injecting 50 μg of type i collagenase into the patellar tendon of 24 Sprague Dawley rats of 7 months of age and weighting 300 g. The sample was divided into 4 groups: the control group, collagenase group, and two EPI(®) technique treatment groups of 3 and 6 mA, respectively. An EPI(®) treatment session was applied, and after 3 days, the tendons were analysed using immunoblotting and electrophoresis techniques. An analysis was also made of cytochrome C protein, Smac/Diablo, vascular endothelial growth factor and its receptor 2, as well as the nuclear transcription factor peroxisome proliferator-activated receptor gamma.

RESULTS

A statistically significant increase, compared to the control group, was observed in the expression of cytochrome C, Smac/Diablo, vascular endothelial growth factor, its receptor 2 and peroxisome proliferator-activated receptor gamma in the groups in which the EPI(®) technique was applied.

CONCLUSIONS

EPI(®) technique produces an increase in anti-inflammatory and angiogenic molecular mechanisms in collagenase-induced tendon injury in rats.

Quadriceps tendon tear rupture in healthy patients treated with patellar drilling holes: clinical and ultrasonographic analysis after 36 months of follow-up

BACKGROUND

quadriceps tendon subcutaneous rupture is an uncommon injury affecting predominantly middle-aged men as a result of direct or indirect trauma; aim of this work is to evaluate clinical outcome and tendon morphology in patients treated surgically with transpatellar drilling suture.

METHODS

20 patients (20 male) with an average age of 54 (42-59) were evaluated with a mean follow-up of 36 months. Measurements of range of motion (ROM) and of tight circumference were collected. Lysholm and Rougraff Score were also performed. All the patients underwent a US evaluation the morphologic changes of the repaired tendon.

RESULTS

mean active ROM was 1°-117°; average difference in the circumference of the quadriceps was 2.6% 10 C and 3.3% 15 C. The mean Lysholm Score calculated was 88/100; the mean Rougraff Score 17/25. At ultrasonographic evaluation all tendons were continuous; heterotopic ossification was present in 18 quadriceps tendons. Thickness was augmented in 18 quadriceps tendons and in 5 patellar tendons. Vascularization was always conserved. Lateral subluxation of patella was reported in 1 case.

CONCLUSIONS

patellar drilling holes repair is a non-demanding procedure, inexpensive and technically uncomplicated. US evaluation confirms tendon healing; tendon remodeling does not affect patient's clinical outcome and quality of life.

LEVEL OF INCIDENCE

IV.

Acute quadriceps tendon ruptures: a series of 50 knees with an average follow-up of more than 6 years

INTRODUCTION

Quadriceps tendon ruptures are rare and mainly affect patients over 40 years of age who have a systemic disease. The aim of this study was to evaluate the functional and radiological outcomes following surgical repair of acute quadriceps tendon ruptures.

METHODS

This retrospective study included 68 knees in 65 patients (three women, 62 men), having an average age of 55.2 ± 13.9 years. The Lysholm and Tegner scores, patient satisfaction, range of motion and X-rays were evaluated.

RESULTS

Fifty knees were evaluated with a mean follow-up of 76±67 months (12-253 months). The average Lysholm score was 93.7±10 (range 56-100, median 99) and 49 of 50 knees (98%) had good or very good subjective results. The average Tegner score was 3.4±1.6 (range 1-9, median 4). At the last follow-up, the average active flexion was 133°±10.8° (range 110°-150°, median 130°). Minor or moderate patellofemoral osteoarthritis was found in 24% of knees, but this was attributed to the surgery or initial injury in only 8% of cases. For 97% of active patients, the surgical repair allowed them to return to work in their pre-injury occupations.

CONCLUSION

Quadriceps tendon ruptures have a good prognosis if they are diagnosed quickly. Treatment consists of surgery and postoperative immobilization for at least 6 weeks. An intensive rehabilitation protocol is also needed to recover good knee function.

LEVEL OF EVIDENCE

Level IV. Retrospective study.

Multiple percutaneous longitudinal tenotomies for chronic Achilles tendinopathy in runners: a long-term study

BACKGROUND

Multiple percutaneous longitudinal tenotomies have been successfully undertaken in runners with isolated midportion Achilles tendinopathy (nodular lesions <2.5 cm) without any sign of paratendinopathy.

HYPOTHESIS

In the long term, minimally invasive multiple tenotomies allow the patient to remain involved in middle- and long-distance running. Clinical and ultrasound (US) evidence of paratendinopathy is a negative prognostic factor.

STUDY DESIGN

Case series study; Level of evidence, 4.

METHODS

A total of 39 patients were reviewed at an average follow-up of 17 years (range, 15-22 years) after US-guided multiple percutaneous longitudinal tenotomies for chronic Achilles tendinopathy. The Victorian Institute of Sports Assessment-Achilles (VISA-A) questionnaire was completed by each patient, maximum calf circumference and isometric plantarflexion strength of the gastrocsoleus complex were measured in both the affected and contralateral legs, and functional assessment was scored by the 4-point Boyden scale. Achilles tendon changes were also assessed according to the grayscale US grading system.

RESULTS

At the final follow-up, the maximum calf circumference and the strength in the operated leg were not significantly different than those measured preoperatively, but they were significantly lower than those on the contralateral side. This did not affect patients' daily or sports activities. All patients had returned to their preinjury working occupation; 20 patients were still active in middle- and long-distance running, with an average current level of sport and function that was 60% ± 13% compared with baseline status (before onset of symptoms). Thirty of 39 patients (77%) reported good or excellent outcomes according to the Boyden assessment. On US assessment, the tendon was generally thicker than the contralateral asymptomatic tendon (average, 7.0 vs 8.7 mm, respectively; P = .003). There was no significant difference (P > .05) when comparing patients with good or excellent Boyden results versus those with fair or poor outcomes. The mean VISA-A score was 78.5, with no significant difference between patients with and without paratendinopathy on US assessment (P > .05). All of the patients who did not return to running or who gave up sports activities had signs of paratendinopathy.

CONCLUSION

This approach to the management of midportion Achilles tendinopathy is safe, has a low cost, and is effective in the long term.