Shortening of patellar tendon after total knee arthroplasty (TKA) was previously reported by several studies. Its etiology still remains controversial. Patellar tendon shortening, a direct cause of patella baja, has a dramatic negative impact in terms of clinical outcomes after TKA. Main objective of this study is to assess the feasibility of utilizing a different technique with Ultrasound that is easy to use, cost-effective and able to eliminate the problem of differential magnification occurring in other techniques which count on standard x-rays and to establish the correlation between clinical outcomes and changes in patellar tendon length and thickness after TKA. The study was designed as prospective cohort and, after a minimum of 4-year-follow up period, 47 knees of 24 patients who had undergone primary TKA without patellar resurfacing were included in the study. All patients were scored with Kujala and HSS scores and all patellar tendons were evaluated with USG regarding their length and thickness. We used conventional grey-scale ultrasound imaging (US) to determine any changes in patellar tendon morphology. All cases were evaluated by the same radiologist. The patellar tendon was examined with the knee in 30° flexion. The flexion angle helped to stretch the extensor mechanism and avoid anisotropy (concavity) of the patellar tendon. The transducer was placed along the long axis of the tendon. The patellar tendon was initially examined in the longitudinal plane in order to measure the total length. Then, total length was divided into three parts and sagittal thickness was calculated at the proximal, median, and distal thirds of the patellar tendon. Both the length and thickness of the tendon were measured before surgery and at the 4th year of follow-up. Of the 47 knees that were included in our study, the mean pre-operative and postoperative length of the patellar tendon was 40.78±6.15 mm and 35.93±4.52 mm. Our results suggested significant shortening of the patellar tendon after primary TKA surgery (p<0.05). Intergroup analysis suggested that reduced sagittal thickness in the proximal third of the tendon was more strongly correlated with an increase in functional outcomes (p<0.05). Our results suggested no significant difference in clinical outcome scores between patients with increased or decreased length of the patellar tendon after TKA (p>0.05). We suggest that determining morphologic changes in sagittal thickness as well as length is important in explaining some of the ambiguous causes of anterior knee pain and impaired clinical outcomes after TKA. More accurate documentation of morphologic changes in the patellar tendon after TKA will certainly help to develop new techniques by surgeons or avoid some existing routines that may harm the tendon. USG is a feasible method for evaluating patellar tendon morphology after TKA but more future studies are needed

An understanding of the remodelling of tendon is crucial for the development of scientific methods of treatment and rehabilitation. This study tested the hypothesis that tendon adapts structurally in response to changes in functional loading. A novel model allowed manipulation of the mechanical environment of the patellar tendon in the presence of normal joint movement via the application of an adjustable external fixator mechanism between the patella and the tibia in sheep, while avoiding exposure of the patellar tendon itself. Stress shielding caused a significant reduction in the structural and material properties of stiffness (79%), ultimate load (69%), energy absorbed (61%), elastic modulus (76%) and ultimate stress (72%) of the tendon compared with controls. Compared with the material properties the structural properties exhibited better recovery after re-stressing with stiffness 97%, ultimate load 92%, energy absorbed 96%, elastic modulus 79% and ultimate stress 80%. The cross-sectional area of the re-stressed tendons was significantly greater than that of stress-shielded tendons. The remodelling phenomena exhibited in this study are consistent with a putative feedback mechanism under strain control. This study provides a basis from which to explore the interactions of tendon remodelling and mechanical environment

Introduction: Patellar tendon is one of the main donor sites for graft. Postoperatively, during the healing procedure there are changes, which we recorded and combined them with the clinical image respectively. Material and Methods: During the period 1998–2001 in Sports Injury Unit, we operated for Anterior Cruciate Ligament insufficiency with autologous Bone Patellar Tendon Bone (BPTB) graft 265 patients. We used autologous BPTB graft from the middle third. We got near the two parts after taking the graft and we sewed very well the peritendon fascia. All patients, with few differentiations, followed the same rehabilitation program. Seventy -seven of them (44 men and 33 women ranging from 17 to 44 years -mean: 24,3 years), were imaged postoperative with MRI at specific intervals from the operation between 3–36 months. In the same time we checked the patients clinically. Results: No one study can answer which is the exact time of satisfying or complete healing. Our study shows elements of scar tissue in the middle third of patellar tendon which is decreasing given time. After the 12th month, the proportion between healthy and scar tissue changes and healthy tissue become dominant. But in some cases scar is still existing even after 36 months. The clinical problems such as anterior knee pain are not existed after the 8th postoperative month. Conclusion: In conclusion, we can say that “regeneration” and healing of patellar tendon occurs mainly during the first postoperative year, but it doesn’t stop after this time. So, we couldn’t recommend this donor site for revision reconstruction before the completion of one year postoperatively

We compared the biological characteristics of extrinsic fibroblasts infiltrating the patellar tendon with those of normal, intrinsic fibroblasts in the normal tendon in vitro. Infiltrative fibroblasts were isolated from the patellar tendons of rabbits six weeks after an in situ freeze-thaw treatment which killed the intrinsic fibroblasts. These intrinsic cells were also isolated from the patellar tendons of rabbits which had not been so treated. Proliferation and invasive migration into the patellar tendon was significantly slower for infiltrative fibroblasts than for normal tendon fibroblasts. Flow-cytometric analysis indicated that expression of α5β1 integrin at the cell surface was significantly lower in infiltrative fibroblasts than in normal tendon fibroblasts. The findings suggest that cellular proliferation and invasive migration of fibroblasts into the patellar tendon after necrosis are inferior to those of the normal fibroblasts. The inferior intrinsic properties of infiltrative fibroblasts may contribute to a slow remodelling process in the grafted tendon after ligament reconstruction

Introduction: Anterior cruciate ligament (ACL) rupture impairs knee stability. Reconstruction of the ACL is therefore performed to restore knee stability and avert risk of subsequent ligament and meniscal injury. Bone-patellar tendon-bone autograft is the most commonly employed technique for ACL reconstruction and considered the “gold standard”. Although 10% postoperative patellar tendon shortening has been reported with this technique, there are no systematic studies assessing the effect of this shortening on patellofemoral joint (PFJ) biomechanics under loading conditions simulating normal physiologic activity. The purpose of this study was to determine if 10% shortening of the patellar tendon affected PFJ biomechanics. Methods: Patellofemoral contact characteristics were evaluated in cadaveric knees before and after patellar tendon shortening. Tendon shortening was performed using a specifically designed device that shortened the tendon without interfering with its anatomic and physiologic integrity. Conditions simulating light physical activity such as level walking were recreated by applying physiological quadriceps loads and corresponding angles of tibial rotation to the PFJ at 15°, 30° and 60° of knee flexion. PFJ contact areas were measured at each position of knee flexion before and after patellar tendon shortening using the silicone oil-carbon black powder suspension squeeze technique (3S technique, . Yao & Seedhom, . Proc Instn Mech Engrs. 1991. ;. 205. :. 69. –72. ). Differences were compared using the Wilcoxon signed rank t-test, with p< 0.05 required for statistical significance. Results: Twelve unembalmed cadaveric knees (median age 81.8 years, 8 female: 4 male) were available for study. Five knees had evidence of osteoarthritic changes, and were rejected. The remaining 7 knees were macroscopically intact and were considered adequate for the experimental procedure. The mean patellofemoral contact areas and stresses determined preoperatively were comparable to those reported in normal knees in previous studies. Following patellar tendon shortening, PFJ contact areas were displaced superiorly on the patellar articular surface and distally on the femoral articular surface. Although the PFJ contact area increased by 17% at 15° of knee flexion (p=0.04), no significant change occurred at 30° or 60° of knee flexion (p> 0.05). Patellofemoral contact stress did not differ before and after patellar tendon shortening (p> 0.05) at any angle of knee flexion. Conclusions: Our results suggest that with light activity such as level walking, a 10% postoperative shortening of the patellar tendon does not alter patellar tracking (in particular contact stresses) and therefore may not impact biomechanics of the patellofemoral joint. Extrapolating these results to the clinical scenario, deleterious consequences on the patellofemoral joint are unlikely after bone-patellar tendon-bone autograft reconstruction of the ACL despite the possibility of postoperative patellar tendon shortening

Introduction: Patients with neglected patellar tendon ruptures present with weakness, instability, extensor lag and sometimes pain. Reports in the literature describe autograft and allograft reconstruction and sometimes quadricepsplasty. Post-operative splintage with a cast or brace is often recommended. Aim: To describe a simple effective method of surgical treatment for neglected ruptures of the patellar tendon. Method: Patients who were included all had neglected patellar tendon ruptures that were initially misdiagnosed or had failed other treatment. Through a midline incision scar tissue was excised and two or three strong cerclage wires were used to approximate the patella and ruptured tendon. The wires were passed from the quadriceps tendon to the absorbable sutures in the tibia. No quadricepsplasty was necessary. Following the surgery immediate mobilisation was initiated without the use of a brace. The wires were removed six months following surgery. Results: Four patients were treated at an average of 29 months following the initial injury. The average follow- up was 26 months (range: 13 to 42 months). The average range of motion was 110 degrees. All patients had improved quadriceps strength, no extensor lag and had returned to work. Conclusion: We have described a simple effective method of treatment without the use of autograft or allograft. The strong cerclage wires allowed immediate mobilisation

Purpose of study. To study the effect of different shoes and orthotics have on patellar tendon tensile forces. Patellar tendinopathy is an overuse injury that affects tennis players and in high impact sports like basketball, volleyball and running has an incidence of 20%. The tensile forces in the patellar tendon can be reliably measured with an intratendinously placed fibre optic tube and wireless transmission device allows for dynamic testing. The biggest strain differentials have been confirmed in jumps from 30cm height. Tennis is played on 3 major different court surfaces and there is a variety of commercially designed tennis shoes on the market. Materials and methods. 6 male tennis players, ages 18–49 were enrolled for this study. A fibre optic cannula was placed in the middle of the proximal pole of patella tendon from lateral to medial direction in the dominant knee. The patellar tendon tensile forces deform the fibre optic cannula in turn modulating the light signal passing through the optic cannula. The drag in the fibre optic sensor signal was used to measure the tensile forces in the patellar tendon. MLTS 700 goniometer were utilized to measure and record the amount of flexion with each jump to standardize results for different shoes and orthotics. Results. The results of patellar tendon tensile forces measurements for different players, different shoes and orthotics showed no trend or statistical difference for any particular shoe or orthotic. Conclusions. Fibre optic measurements of the effect of different shoes on patellar tendon tensile forces did not show a distinct advantage for any shoe above another. 1 DISCLOSURE

In order to clarify the role of cytokines in the remodelling of the grafted tendon for ligament reconstruction we compared the responses to interleukin (IL)-1β, platelet-derived growth factor (PDGF)-BB and transforming growth factor (TGF)-β1 of extrinsic fibroblasts infiltrating the frozen-thawed patellar tendon in rats with that of the normal tendon fibroblasts, in regard to the gene expression of matrix metalloproteinase (MMP)-13, using Northern blot analysis. We also examined, immunohistologically, the local expression of IL-1β, PDGF-BB, and TGF-β1 in fibroblasts infiltrating the frozen-thawed patellar tendon. Northern blot analysis showed that fibroblasts derived from the patellar tendon six weeks after the freeze-thaw procedure in situ showed less response to IL-1β than normal tendon fibroblasts with respect to MMP-13 mRNA gene expression. The immunohistological findings revealed that IL-1β was over-expressed in extrinsic fibroblasts which infiltrated the patellar tendon two and six weeks after the freeze-thaw procedure in situ, but neither PDGF-BB nor TGF-β1 was over-expressed in these extrinsic fibroblasts. Our findings indicated that IL-1β had a close relationship to matrix remodelling of the grafted tendon for ligament reconstruction, in addition to the commencement of inflammation during the tissue-healing process

We performed a biomechanical and histological study to clarify the effect of stress enhancement on the in situ frozen-thawed patellar tendon of the rabbit as a tendon autograft model. We used 48 Japanese White rabbits divided into three groups. In group 1, the patellar tendon underwent in situ freeze-thaw treatment with liquid nitrogen to kill intrinsic fibroblasts. In group 2, after similar treatment, the medial and lateral portions were resected so that the cross-sectional area was reduced by a third. In group 3, after treatment, the cross-sectional area was reduced by a half. In groups 2 and 3, the stress in the tendon was calculated theoretically to be 150% and 200% of the physiological stress during locomotion. Eight rabbits in each group were killed at three and six weeks, respectively. At three weeks, the mean values for the tensile strength of groups 2 and 3 were 113.7% and 75.7% of that of group 1, and at six weeks 101.2% and 57.4%, respectively. The tensile strength in group 3 was significantly lower than that in groups 1 and 2. The histological findings in group 2 were similar to those in group 1, although an acellular area appeared to be wider in the core portion compared with group 1 at each period. In group 3, the collagen bundles of the tendon were less organised than those of groups 1 and 2. Our findings showed that stress enhancement affects the remodelling of the frozen-thawed patellar tendon and that excessively high stress reduces the mechanical properties of the tendon. This indicates that high stress on the patellar tendon autograft should be avoided during ligament reconstruction

Obesity decreases patellar tendon stiffness in females but not males Introduction Patellar tendon (PT) injuries are frequent due to excessive mechanical loading during strenuous physical activity. PT injury incidence is higher in females and obese individuals. The reason behind higher tendon injury incidence in females and obese individuals might be structural changes in tendons such as stiffness or elasticity. Tendon stiffness can recently be quantified using shear wave elastography (SWE). We aimed to examine the stiffness of PT in healthy sedentary participants using this new technology. This prospective study was carried out with 58 (34 female, 24 male) healthy sedentary participants between the ages of 18–44 years (27.5±7.7 years). Body mass and body fat percentage were measured with the Bioelectrical Impedance method using Tanita BC-418 MA Segmental Body Composition Analyser (Tanita Corporation, Tokyo, Japan). Participants were subsequently categorized into ‘normal-weight’ (BMI < 23 kg/m2) and ‘obese’ (BMI>27.5 kg/m2). SWE of the PT was measured with the ACUSON S3000 (Siemens Medical Solution, Mountain Wiew, CA, USA) ultrasound device using the Siemens 9L4 (4–9 MHz) linear-array probe with the Virtual Touch Imaging Quantification® method. The measurement was performed by placing the US probe longitudinally on patellar tendon with knee flexed at 30°. The region between about 1 cm distal of patellar bone-tendon junction and 1 cm proximal of bone-tendon junction of tibia was used for PT stiffness measurement (Figure 1). Average of three successive measurements at 10 sec intervals was recorded as PT stiffness. PT stiffness was quantified with MATLAB Version 2015 (Mathworks, Massachusetts, USA) by converting colour data into numbers. PT stiffness, in males, in females, in normal males, in obese males, in normal females, and in obese females was 8.6±1.0 m/sec, 7.4±1.1 m/sec, 8.6±1.1 m/sec, 8.5±1.0 m/sec, 7.9±0.9 m/sec, and 6.2±0.9 m/sec, respectively. Average body fat percentage in males, in females, in normal males, in obese males, in normal females, and in obese females was 20.1±7.4 kg/m2, 30.1±8.1 kg/m2, 15.4±5.2 kg/m2, 24.7±4.6 kg/m2, 25.6±5.5 kg/m2, and 38.1±5.0 kg/m2, respectively. Males PT stiffness was higher when compared to that of females (p=0.000). PT stiffness was similar in obese and normal males (p=0.962) but obese females had lower PT stiffness compared to normal females (p=0.001). PT stiffness of females was lower than males and obesity decreased PT stiffness in females but not in males. The possible explanation of lower PT stiffness in females might be due to their higher estrogen levels that lead to a decrease in estradiol level and collagen synthesis. Lower tendon stiffness in obese females might be metabolic effects due to the increased adipose tissue that contains proteins such as adipokinome, chemerin, lipocalin 2, serum amyloid A3 and adiponectin. These proteins lead to disturbance of tendon homeostasis and decreased collagen content. Altered tendon homeostasis and decreased collagen content may lead to a decrease in tendon stiffness. Decreased PT stiffness in especially in obese women might be associated with increased risk of PT injury

Abstract. Objectives. The need for gender specific knee arthroplasty is debated. This research aimed to establish whether gender differences in patellar tendon moment arm (PTMA), a composite measure that characterises function of both the patellofemoral and tibiofemoral joints, are a consequence of knee size or other variation. Methods. PTMA about the instantaneous helical axis was calculated from positional data acquired using optical tracking. First, data post-processing was optimised, comparing four smoothing techniques (raw, Butterworth filtered, generalised cross-validation cubic spline interpolated and combined filtered/interpolated) using a fabricated knee. Then PTMA was measured during open-chain extension for N=24 (11 female) fresh-frozen cadaveric knees, with physiologically based loading and extension rates (420°/s) applied. Gender differences in PTMA were assessed before and after accounting for knee size with epicondylar width. Results. Combined smoothing enabled sub-mm accuracy (root-mean-squared (RMS) error 0.16mm, max error 0.47mm), whereas large errors were measured for raw (RMS 3.61mm, max 23.71mm), filtered-only (RMS 1.19mm, max 7.38mm) and interpolated-only (RMS 0.68mm, max 1.80mm) techniques. Before scaling, average PTMA throughout knee flexion was 46mm and mean, maximum, and minimum absolute values of PTMA were larger in males (mean differences >8mm, p<0.001), as were the PTMAs at terminal extension and flexion, and the change in PTMA from peak to terminal extension (differences >4mm, p<0.05). After scaling, the PTMA in deep flexion and the change in PTMA from peak to terminal extension were still larger in male knees (differences >2mm, p<0.05). The flexion angle of peak PTMA, unaffected by scaling, was closer to terminal extension for female knee (female 15°, male 29°, p<0.05). Conclusion. Gender differences in PTMA were identified both before and after accounting for knee size, with implications for gender-specific arthroplasty and musculoskeletal models. The developed measurement framework could also be applied in vivo for accurate measurement of the PTMA. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Two men, aged 21 and 50 years, were seen with ossification of the patellar tendon after injury to the knee in adolescence. They complained of pain and had patella alta. Large bony masses were excised from below the affected patellae. The patellar tendon was then reconstructed using a Leeds-Keio ligament. The results at six and ten years, respectively, were good, with neither patient having pain or an extension lag

Tendons and ligaments are similar in composition but differ in function. Simple anatomical definitions do not reflect the fact individual tendons and ligaments have unique properties due to their adaptation to a specific role. The patellar tendon is a structure of particular clinical interest. A null hypothesis was declared stating that the patellar tendon is not significantly different in terms of matrix composition and collagen fibril diameter to other tendons. The lateral and medial collateral ligaments (LCL, MCL), anterior and posterior cruciate ligaments (ACL, PCL), together with the long digital extensor, superfi-cial digital extensor and patellar tendons (LDET, SDFT, PT) were harvested from 3 cadaveric ovine hindlimbs. The extracellular matrix was assessed in terms of water, collagen and total sulphated glycosaminoglycan (GAG) content. The organisation of the collagen component was determined by an ultrastructural analysis of collagen fibril diameter distributions using electron microscopy, together with values for the collagen fibril index (CFI) and mass-average diameter (MAD). There were significant differences between ligaments and tendons. The PT had a bimodal collagen fibril diameter distribution with CFI72.9%, MAD 202nm, water content 53.1%, GAG content 2.3 g/mg and collagen content 73.7%, which was not significantly different from the other tendons. The results of this study support the null hypothesis suggesting that the patellar tendon is similar to other tendons and demonstrate that tendons have different characteristics to ligaments

We studied changes in patellar tendon length after reconstruction of the anterior cruciate ligament using either the medial third of the patellar tendon as a graft (n = 40) or a Leeds-Keio artificial ligament (n = 40). Both types of ligament replacement had been supplemented with a MacIntosh extra-articular lateral substitution. The mean change in length in the tendon graft group was 6% (SD 5.39); in the Leeds-Keio group it was 2.4% (SD 4.93). The change in length was significant in both groups, but shortening was more frequent and more severe in the tendon graft group. There was shortening of 10% or more in 25% of knees after patellar tendon graft and 7.5% after use of a Leeds-Keio prosthesis

We describe a new method for reconstructing the patellar tendon following combined injury to the patellar tendon and anterior cruciate ligament (ACL). Combined injuries to the patellar tendon and the ACL represent a rare and potentially serious injury pattern. The injury to the patellar tendon can often go undiagnosed at primary presentation. Reconstructive options for the patellar tendon are described but can be technically difficult, particularly if ipsilateral hamstring has been used for anterior cruciate ligament reconstruction. Evidence suggests combined injuries generally lead to poor long term outcome. We describe a case of a 26 year old male who presented with a reconstructed ACL and a patellar tendon deficient knee. Diagnosis was confirmed on Magnetic Resonance Imaging (MRI). Ipsilateral hamstrings had been used as donor for ACL reconstruction. An Achilles tendon allograft with distal bone block was used in combination with contralateral semitendinosus and gracilis autograft to reconstruct the three bundles of the patellar tendon. The patient experienced no postoperative complications and was followed up radiologically and clinically. Computer Topography imaging performed at 6 months post-operatively showed union of the bony Achilles tendon block. MRI performed 1 year post-operatively showed good incorporation of the tendinous grafts and no evidence of degeneration or tearing. Oxford knee score at 6 months post-operatively was 31/48. One year post-operatively full pre-injury activity level had been achieved. We believe this method to provide adequate strength and integrity, enabling early rehabilitation following this rare injury. It has also been shown to give a good functional outcome

Patella infera can cause knee pain and lead to patellofemoral osteoarthritis. Treatment is usually unsatisfactory. We describe a case of severe patella infera after operative treatment for fracture of the patella. We used Ilizarov external fixation and gradual lengthening of the patellar tendon. The patellar height was restored and the patient’s symptoms were much improved

Aims: To evaluate the morphologic changes in the patellar tendon 10 years after harvesting its central third for reconstruction of the anterior cruciate ligament, and examine the association between the morphologic changes and the occurrence of anterior knee pain of the patients. Methods: Thirty-one patients who had undergone an anterior cruciate ligament reconstruction using central-third bone-patellar tendon-bone autograft with a closure of the patellar tendon defect were included in this study. An ultrasonographic and Power Doppler examination was performed at a mean follow-up of 10 years. Results: Ultrasonography of the harvested patellar tendon showed intratendinous calcification in 9 patients, hypoechoic lesion in 20 patients, hyperechoic lesion in one patient, and peritendinous changes in one patient. No abnormality was visible in the contralateral (normal) patellar tendons of the 31 patients. The harvested patellar tendon was significantly thicker than the contralateral patellar tendon both at the proximal third (p=0.017) and at the distal third (p=0.020) of the tendon. Patellar osteophytes were more common in patients with anterior knee pain than without it (p=0.05). Conclusions: Sonographic morphologic changes of the patellar tendon were common 10 years after the harvesting procedure. Also, the harvested patellar tendon was significantly thicker than the normal patellar tendon

Introduction: Patello-femoral instability (PFI) and pain may be caused by anatomical abnormality. Many radiographic measurements have been used to describe the shape and position of the patella and femoral trochlea. Some are difficult to apply when dysplasia is present. This paper describes a simple new MRI measurement of the axial patellar tendon angle (APTA), and compares this angle in patients with and without patello-femoral instability. Method: Axial MRI images of the knee of 20 patients with PFI and 20 normal knees (isolated acute ACL rupture) were used for measurement. The angle between the patellar tendon and the posterior femoral condylar line was assessed at three levels from the proximal tendon to its insertion. Results: In normal knees, the APTA is 11 degrees of lateral tilt at all levels from the proximal tendon to its distal insertion. In PFI knees, the APTA is 32 degrees at the proximal tendon, 27 degrees at the joint line and 22 degrees at the distal insertion. The difference is significant (p< 0.001) at all levels. Discussion: Measurement of the APTA is reproducible and is easier than many other indices of patello-femoral anatomy. In PFI, the APTA is increased by 21 degrees at the proximal tendon and by 11 degrees at its distal insertion. In PFI, the patella is commonly tilted laterally. This is matched by the orientation of the patellar tendon. The increased tilt of the tendon is only partially corrected at its distal insertion with an abnormal angle of tibial attachment. When performing distal realignment procedures, angular correction as well as displacement may be appropriate

Objective: The aim of this study was to compare different patellar tendon repair constructs. Materials and Methods: Eight pairs of cadaveric legs were used to compare metal suture anchor repair with “standard” Krakow tendon suture through patella bone tunnels and steel box wire augmentation loop repair. Each leg was retested with box wire augmentation loop and simple 2/0 polyglactin suture repair. The repairs were tested by mounting the legs on a specially designed rig on a materials testing machine which allowed the leg to be cycled from 90° knee flexion to full extension. The specimens were cycled 1000 times at 0.25Hz or until the repair failed. Optical markers were attached to the leg which enabled the repair gap and knee angle to be monitored during testing (Smart Capture and Analyser Tracking system, Padua, Italy). Results: Six out of eight suture anchor repairs failed, all suture bone tunnel repairs with augmentation loops completed 1000 cycles. One out of 16 augmentation loop with simple 2/0 suture repair failed. For all specimens regardless of repair type that completed 1000 cycles there was no significant difference in repair gap distance. Conclusion: Suture anchors alone do not provide a strong enough construct for patellar tendon repair. The box wire augmentation loop is key to maintaining patellar tendon repair. Krakow tendon sutures secured through patellar bone tunnels do not provide additional benefit to a simple appositional suture and box wire augmentation loop

Patella infera may occur after reconstruction of the anterior cruciate ligament (ACL), high tibial osteotomy and total knee replacement (TKR). Restriction of movement of the knee and pain may result. Our aim was to compare the incidence and to assess the effects of patella infera after TKR and unicompartmental knee replacement (UKR). We reviewed radiographs of the knees of 84 patients who had had either TKR or UKR as part of a randomised, controlled trial. The length of the patellar tendon was measured on serial radiographs taken before, at eight months and at five years after operation. There was no significant change in the length of the patellar tendon after UKR, but a significant reduction was observed after TKR. Five years after the operation, the shortening of the tendon had increased to a mean of 3.5 mm. Of the knees with TKR reviewed at five years, 34% developed patella infera, defined as 10% or more of shortening, compared with 5% of those with UKR. Shortening was greatest in those knees which had required a lateral release; in this subgroup the mean shortening was 7.2 mm. Shortening correlated with restriction of movement and pain in the knee. Our study has shown that patella infera develops in most patients after TKR with lateral release, and in approximately 25% of patients after TKR without this additional procedure. Patella infera rarely occurs after UKR. It is associated with restriction of movement and pain in the knee. It may be an effect of the more extensive exposure required to perform TKR and may, in part, explain the better clinical results of UKR

Purpose of the study: The issue of which graft to choose for anterior cruciate ligament (ACL) reconstruction is still a matter of debate. An analysis of the literature reveals the difficulty encountered when performing comparative trials. It is also difficult to demonstrate significant differences with results obtained with an insufficient number of patients. We propose here a meta-analysis in order to combine the results obtained with different comparative studies. Material and methods: The literature search (Medline 1990–2005) was based on the following selection criteria: ACL reconstruction, patellar tendon (PT), gracilis and semitendinous (four-strand hamstring) reconstruction and comparative prospective study. Studies were retained with: > 30 patients per group, minimum follow-up 24 months, IKDC score. Evaluation criteria retained were: anterior pain, resumed activity, IKDC score, differential laxity. The relative risk (RR) statistical method with 95% confidence interval (CI) was applied. Means were calculated and the chi-square and z-tests were applied. Results: Thirteen studies satisfied our inclusion criteria. These studies had included more than 1300 transplants. Mean rate of anterior pain was 23.2% with PR and 17.3% with hamstring reconstructions. The RR was 0.73 with a CI different from 1. The difference was significant. Resumption of sports activities at the same level, subjective assessment, number of failures, and overall IKDC score were not statistically different between the two types of transplants. The IKDC laxity score was not different but the residual maximal manual differential laxity was greater in the hamstring patients than in the patellar patients in 80% of the cases. Conclusion: At the observed follow-up, free grafting with a four-strand hamstring tendon or a patellar tendon is an effective method for reconstruction of the ACL. Anterior pain is more frequent with the patellar tendon method and residual laxity is greater with the hamstring method. The long-term outcome will determine whether the residual laxity observed with the hamstring graft has a deleterious effect on the meniscocartilaginous structures. This criteria would minimize the advantage of this technique over the patellar tendon technique concerning the initial anterior pain

INTRODUCTION. Patellar tendon (PT) autograft is an excellent choice repairing anterior cruciate ligament (ACL) ruptures. Published studies testing the biomechanical characteristics after plasty usually refer to grafts with 10mm wide. The thickness of PT and geometry of the patella have been overlooked. The purpose of this study was to understand the geometry of PT and patella in our population, regarding their use in Bone - Patellar Tendon - Bone (BTB) technique, in order to evaluate their biomechanical efficiency and study their relationship with anthropometric parameters. MATERIAL. 100 individuals (50/50) who underwent knee MRI (3-Tesla). Ages between 18–65years. METHODS. Retrospective study. Standardized protocol for measuring the PT and patella based in MRI images. Interview to obtain personal data. Statistical analysis using SPSS®. RESULTS. Sample (mean ±SD): age 41 ±14years, weight 73 ±12kg, height 167 ±10cm, BMI 26,04 ±4,13; length PT/patella −41,3 ±6,1mm/29,6 ±4,2 mm, width PT/patella −25,3 ±3,2mm/43,4 ±4,14mm; thickness PT −3,79 ±1,01mm/22,8 ±2,2mm; Men have thicker and wider patella and PT than women (p<0.001). The patella is also longer in males (p<0.001). There is statistical significant relationship between weight and height to width, thickness and length of PT and patella (p<0.01). Body Mass Index (BMI) doesn't have statistical correlation with geometry of the PT and patella. DISCUSSION. The PT remains as an excellent option in ACL repair. The anatomy and quality of the graft are essential to achieving good functional results. The choice of middle third tendon to the BTB plasty does not always correspond to the 10mm width, as used in most biomechanical tests. Also patellar integrity can be at risk (when collecting the bone block) if patella geometry is not considered. To our knowledge, there is only one similar study in literature, preformed in Asian individuals. CONCLUSION. Preoperatively accessing the geometry of Patella and PT can be crucial in obtaining efficient grafts and decreasing morbidity over the extensor mechanism

As treatments of knee osteoarthrosis are continually refined, increasingly sophisticated methods of evaluating their biomechanical function are required. Whilst TKA shows good preoperative pain relief and survivorship, functional outcomes are sub-optimal, and research focus has shifted towards their improvement. Restoration of physiological function is a common design goal that relies on clear, detailed descriptions of native biomechanics. Historical simplifications of true biomechanisms, for example sagittal plane approximation of knee kinematics, are becoming progressively less suitable for evaluation of new technologies. The patellar tendon moment arm (PTMA) is an example of such a metric of knee function that usefully informs design of knee arthroplasty but is not fully understood, in part due to limitations in its measurement. This research optimized PTMA measurement and identified the influence of knee size and sex on its variation. The PTMA about the instantaneous helical axis was calculated from optical tracked positional data. A fabricated knee model facilitated calculation optimization, comparing four data smoothing techniques (raw, Butterworth filtering, generalized cross-validated cubic spline-interpolation and combined filtering/interpolation). The PTMA was then measured for 24 fresh-frozen cadaveric knees, under physiologically based loading and extension rates. Sex differences in PTMA were assessed before and after size scaling. Large errors were measured for raw and interpolated-only techniques in the mid-range of extension, whilst both raw and filtered-only methods saw large inaccuracies at terminal extension and flexion. Combined filtering/interpolation enabled sub-mm PTMA calculation accuracy throughout the range of knee flexion, including at terminal extension/flexion (root-mean-squared error 0.2mm, max error 0.5mm) (Figure 1). Before scaling, mean PTMA throughout flexion was 46mm; mean, peak, and minimum PTMA values were larger in males, as was the PTMA at terminal flexion, the change in PTMA from terminal flexion to peak, and the change from peak to terminal extension (mean differences ranging from 5 to 10mm, p<0.05). Knee size was highly correlated with PTMA magnitude (r>0.8, p<0.001) (Figure 2). Scaling eliminated sex differences in PTMA magnitude, but peak PTMA occurred closer to terminal extension in females (female 15°, male 29°, p=0.01) (Figure 3). Improved measurement of the PTMA reveals previously undocumented characteristics that may help to improve the functional outcomes of knee arthroplasty. Knee size accounted for two-thirds of the variation in PTMA magnitude, but not the flexion angle at which peak PTMA occurred, which has implications for morphotype-specific arthroplasty and musculoskeletal models. The developed calculation framework is applicable both in vivo and vitro for accurate PTMA measurement and might be used to evaluate the relative performance of emerging technologies. For any figures or tables, please contact the authors directly

Introduction: Patello-femoral instability (PFI) and pain may be caused by anatomical abnormality. Many radiographic measurements have been used to describe the shape and position of the patella and femoral trochlea. This paper describes a simple new MRI measurement of the axial patellar tendon angle (APTA), and compares this angle in patients with and without patello-femoral instability. Method: Axial MRI images of the knee of 20 patients with PFI and 20 normal knees (isolated acute ACL rupture) were used for measurement. The angle between the patellar tendon and the posterior femoral condylar line was assessed at three levels from the proximal tendon to its insertion. Results: In normal knees, the APTA is 11 degrees of lateral tilt at all levels from the proximal tendon to its distal insertion. In PFI knees, the APTA is 33 degrees at the proximal tendon, 28 degrees at the joint line and 22 degrees at the distal insertion. The difference is significant (p< 0.001) at all levels. Discussion: Measurement of the APTA is reproducible and is easier than many other indices of patello-femoral anatomy. In PFI, the APTA is increased by 21 degrees at the proximal tendon and by 11 degrees at its distal insertion. In PFI, the patella is commonly tilted laterally. This is matched by the orientation of the patellar tendon. The increased tilt of the tendon is only partially normalized at its distal insertion with an abnormal angle of tibial attachment. When performing distal realignment procedures, angular correction as well as displacement may be appropriate

Patello-femoral instability (PFI) and pain may be caused by anatomical abnormality. Many radiographic measurements have been used to describe the shape and position of the patella and femoral trochlea. This paper describes a simple new MRI measurement of the axial patellar tendon angle (APTA), and compares this angle in patients with and without patello-femoral instability. Method: Axial MRI images of the knee of 20 patients with PFI and 20 normal knees (isolated acute ACL rupture) were used for measurement. The angle between the patellar tendon and the posterior femoral condylar line was assessed at three levels from the proximal tendon to its insertion. Results: In normal knees, the APTA is 11 degrees of lateral tilt at all levels from the proximal tendon to its distal insertion. In PFI knees, the APTA is 33 degrees at the proximal tendon, 28 degrees at the joint line and 22 degrees at the distal insertion. The difference is significant (p< 0.001) at all levels. Discussion: Measurement of the APTA is reproducible and is easier than many other indices of patello-femoral anatomy. In PFI, the APTA is increased by 21 degrees at the proximal tendon and by 11 degrees at its distal insertion. In PFI, the patella is commonly tilted laterally. This is matched by the orientation of the patellar tendon. The increased tilt of the tendon is only partially normalized at its distal insertion with an abnormal angle of tibial attachment. When performing distal realignment procedures, angular correction as well as displacement may be appropriate

Introduction and Aims: We present the preliminary results of patellar tendon shortening (PTS), for severe crouch gait in children with spastic cerebral palsy who were household ambulators. Method: We performed bilateral patellar tendon shortening in 15 patients with severe spastic diplegia between May 1996 and January 2002. The majority had acquired crouch gait because of isolated lengthening of the Achilles tendons in childhood and presented with anterior knee pain and rapidly deteriorating gait and function. The PTS procedure included dividing the patellar tendon in its mid portion, and performing an overlapping repair by suturing the distal tendon to the distal pole of the patella and the proximal segment to the tibial tubercle. The corrected position of the patella was maintained by a K-wire passed transversely through the patella and incorporated into a cylinder plaster, with the knee in extension, for a period of six weeks. Correction of knee flexion deformity was achieved by transfer of semitendonosis to the distal femur or extension osteotomy of the distal femur. Results: Rehabilitation was predictably slow but all patients regained their pre-operative mobility status within one year and the majority surpassed their pre-operative functional level by two years after surgery. There were no tendon ruptures or growth disturbance in the proximal tibia. Average age at the time of surgery was 14.2 years (10–19 years). Mean follow-up was 27 months (12–48 months). Pre- and post-operative Insall index in 17 knees was 0.68cm (0.46 to 1.07cm, SD=0.16cm) and 0.85cm (0.56 to 1.08cm, SD=0.20) respectively (p< 0.001 Students-t test). Pre-operatively, only three sides had a normal index, but post-operatively 14 sides had a normal index. Crouch gait improved in all patients who were reclassified as community ambulators. Thirteen patients still needed crutches. One patient continued to complain of bilateral knee pain 12 months after surgery, had insufficient correction according to the Insall index (0.58cm on the left 0.56cm on the right). Conclusion: Severe crouch gait after appropriate surgical and orthotic management, maybe due to patella alta, quadriceps and ankle plantarflexors insufficiency. We present preliminary results of a salvage procedure, patellar tendon shortening, which seems a reasonable option to treat complex crouch gait in selected patients with cerebral palsy

It appears that double bundle anterior cruciate ligament reconstruction can reproduce the original anatomy of the ligament, restoring normal kinematics and rotational control of the tibia. But an anatomical single bundle reconstruction may present very similar results, with minor technical difficulties and lower costs. We compared two groups of 25 patients each, that underwent ACL reconstruction by the same surgeon, with a follow-up of 12–36 months. One group had double bundle reconstruction with hamstring and the other had single bundle anatomical reconstruction with patellar tendon. Patients underwent a subjective evaluation and clinical testing with instrumented laxity with Rolimeter, and the data entered in the IKDC 2000 scale Double tunnel hamstring Vs bone-tendon-bone: Functional outcome of 85.6% Global Class A and B vs. 82.1% Class A and B. The subjective outcome (IKDC 2000) was 90.93 vs. 91.47. Pivot-shift test with 87% patients in class A and class B at 9.7% Vs 75% patients in class A, 21.4% for class B. The Rolimeter gave an average Lachman value of 2,56 and anterior drawer test of 2,88 Vs average Lachman value of 3.59 and anterior drawer test of 2.92. One leg hop test showed 85.7% knees class A, 9.5% knees class B vs. 90.4% knees class A and, 2.8% knees class B. The subjective score was slightly higher in the single bundle anatomical reconstruction with patellar tendon, despite the overall functional outcome being higher in the double tunnel technique with hamstrings. The average Lachmann in the patellar tendon group was 1 mm higher. The rotational stability in the double tunnel was higher. The same surgeon had better results in the double tunnel hamstrings technique, despite less experienced with this technique, which is more demanding, probably reflecting objective advantages over the single bundle reconstruction with patellar tendon

Purpose: This study sought to compare clinical outcomes and return to activity in high-demand patients following ACL reconstruction with either autograft or allograft patellar tendon using a matched-pairs case-control experimental design. Method: Nineteen matched pairs were obtained based on gender (36.8 % female), age (27.9±8.1yrs autograft versus 28.1±9.1 allograft), and length of follow-up (9.1±2.7yrs autograft versus 10.3±2.6 allograft). All patients reported participating in very strenuous (soccer, basketball etc.) or strenuous (skiing, tennis etc.) sporting activity 4–7 times/ week prior to their knee injury. Patient-reported outcomes included the IKDC Subjective Knee Form, Activities of Daily Living (ADLS) and Sports Activity Scales (SAS) of the Knee Outcome Survey and SF-36. Range of motion, laxity, and functional strength were also assessed. Results: There were no significant differences in patient-reported or clinical outcome measures. Sixteen (84.2%) subjects undergoing autograft reconstruction and 12 (63.2%) subjects reconstructed with allograft were able to participate in strenuous or very strenuous sporting activity at follow-up (p=.34). Similar percentages of subjects were able to return to their pre-injury level of sports activity [12 (63.2%) autograft vs. 11 (57.9%) allograft; p=1.0]. Fewer subjects undergoing reconstruction with autograft reported instability with very strenuous activity [5 (26.3%) autograft vs. 12 (63.2%) allograft], but this difference was not significant (p=.07). Conclusion: While autograft and allograft patellar tendon ACL reconstruction exhibit similar clinical outcomes in high-demand individuals, autogenous patellar tendon grafts may be indicated to allow patients to return to very strenuous levels of activity

The February 2023 Knee Roundup. 360. looks at: Machine-learning models: are all complications predictable?; Positive cultures can be safely ignored in revision arthroplasty patients that do not meet the 2018 International Consensus Meeting Criteria; Spinal versus general anaesthesia in contemporary primary total knee arthroplasty; Preoperative pain and early arthritis are associated with poor outcomes in total knee arthroplasty; Risk factors for infection and revision surgery following patellar tendon and quadriceps tendon repairs; Supervised versus unsupervised rehabilitation following total knee arthroplasty; Kinematic alignment has similar outcomes to mechanical alignment: a systematic review and meta-analysis; Lifetime risk of revision after knee arthroplasty influenced by age, sex, and indication; Risk factors for knee osteoarthritis after traumatic knee injury

Purpose of the study: For medial osteoarthritis with chronic anterior laxity, we propose an original technique combining subtraction osteotomy and extra-articular ligmentoplasty using the lateral quarter of the patellar tendon. Material and methods: WE report a retrospective review of 29 patients (11 males/18 females) aged 29–51 years treated from May 1996 to October 2002. Time from rupture of the anterior cruciate ligament (ACL) and the operation was 17.5 years (range 13–22 years). These patients had had 52 prior operations (more than one per knee). All presented functional instability, a positive pivot test, and anterior laxity measured at 8 mm on average (range 5–10 mm) on KT1000. Pain in the medial compartment was observed in all patients with osteoarthritis noted grade II in 7, grade III in 18 and grade IV in 4. Radological varus measured 5–15°. Lateral subtraction osteotomy fixed with a plate was performed in combination with a patellar tendon autograft using the lateral quarter of the patellar tendon. Immediate mobilization with complete weight bearing was the rule. Results: A mean 5–year follow-up (range 18 months to 9 years). According to the IKDC subjective score, 26 patients were satisfied or very satisfied and 22 of them had resumed their sports activities. Instability persisted in one patient and pain in two. Varus was corrected in three patients but the medial degradation progressed. Anterior laxity measured with KT1000 was 1–6 mm (mean 2 mm). The pivot test was positive in one knee, negative in 18 and revealed slight displacement in 10. Excluding the radiological aspect, the overall IKDC score was 2A, 21B, 6C, 1D. Conclusion: This combined method is particularly interesting for stabilizing chronic ACL instability causing secondary medial degeneration. It treats two conditions with the same approach with an acceptable rate of satisfaction

Purpose: Patellar tendonitis (i.e. jumper’s knee) commonly affects young adult athletes who use their knee extensor mechanism in a repetitive and/or intense manner, such as in basketball and volleyball. There is a small but significant percentage of patients with persistent symptoms despite at least a six-month course of conservative management. For these patients, we perform knee arthroscopy and open patellar tendon debridement. This study presents the indications, technique, and clinical results of open patellar debridement. Method: We investigated the clinical outcomes of 38 consecutive cases of open patellar tendon debridements (3 were bilateral) in 35 patients without previous open ipsilateral knee surgery over 7 years. Results: Two patients (2 knees) were lost to follow-up (94% follow-up rate). The average age at surgery was 29 (SD 10, range 14–51). There were 21 males and 12 females. At an average follow-up of 43 months (SD 21, range 15–92 months), the Lysholm score showed 27 knees with good or excellent results, 4 fair, and 2 poor. The average post-operative IKDC score was 79 (SD 14, range 41–100). When compared to the pre-operative value, the post-operative Tegner Activity Scores showed no change (average change 0, SD 2, p=0.20), and Visual Analog Pain Scores decreased by an average of 6 points (SD 3, p< 0.001). Twenty-seven patients were completely or mostly satisfied with the surgical outcome, 4 were somewhat satisfied, and 2 were dissatisfied. Twenty-seven patients (82%) said that they would have the surgery performed again for the same problem. Conclusion: Patellar tendon debridement significantly reduces knee pain in patellar tendonitis patients without significantly affecting their activity level; the great majority of patients are satisfied with the results of the procedure

Purpose of the study: to prospectively evaluate if day surgery influences post-operative rehabilitation time in sportsmen. Material and Methods. 122 young sportsmen underwent a reconstruction of the ACL with patellar tendon. They were randomly divided up into two groups. Group A (62 patients, mean age 28 years) Day Surgery and Group B (60 patients, mean age 30 years) staying one or two nights in the clinic. In all the same surgical technique by the same surgeon was performed. Peripheral anaesthesia was used in the majority of them. 15% of the subjects in Group A and 17% of the subjects in Group B chose general anaesthetic. The same rehabilitation protocol was applied to all of the subjects. Results were evaluated with the IKDC form. Furthermore, the time crutches were used, the time needed in order to recover complete ROM and the time lapse from surgery to resuming running and sports activities were evaluated. The results were analysed statistically ( paired Student t test). Mean follow up 75 months. Results. The two groups were classified according to the IKDC form:Group A: 53 A , 6 B , 3 C . Group B: 44 A , 14 B, 2 C. The time crutches were used (mean 10 days in both groups) and the average time needed for the recovery of complete mobility was 88 days in Group A and 105 days in Group B. 8% of Group A and 3% of Group B did not recover flection completely (< 5). Patients in Group A started running after an average time of 92 days, and in Group B after an average time of 110 days. 87% in Group A and 83% in Group B resumed sports activities after 161 and 179 days respectively. No statistical difference was evidenced in any parameter evaluated. 97% in group A declared that they were satisfied with the day surgery. Conclusions and Significance. Day surgery ACL reconstruction does not jeopardize the rehabilitation time of sportsmen

Introduction. Tendon injuries remain challenging, secondary healing and prolonged immobilisation result in suboptimal outcome. Previous study by our group showed that demineralised bone matrix (DBM) can result in faster healing of a tendon enthesis. The aim of this study is to test different ways augmenting tendon with DBM to enhance tendon repair and regeneration. Methods. DBM strips were prepared from tibias of mature ewes. Patella, patellar tendon and tibias were dissected and the distal 1 cm of the patellar tendon was excised. 4 models were designed;. Model-1, DBM strip was used to bridge the gap between the tendon and the tibial tuberosity. The DBM strip was stitched to the tendon using one bone anchor. Model-2, similar to model 1 with the use of 2 anchors. Model-3, similar to model 2, construct was off loaded by continuous thread looped twice through bony tunnels sited in the patella and in the tibial tuberosity. Model-4, similar to model 3 with 3 threads as off loading loop. All models were tested for pullout force and mode of failure. Results. The median failure force for model-1 (N=5) was 250N while for model-2 (N=5) was 290N. In model-3 and model-4 failure of the off loading loop was used as end point, 6 samples were tested in each model. Median failure force of model-3 was 767N and for model-4 was 934N. There was no statistical significance between model-1 and model-2 (p=0.249), however statistical significance was found between other models (p=< 0.006). Discussion. A study published in 1996 proved that cortical DBM can be used as ACL graft with evidence of ligamentisation. DBM provides a biologic scaffold with potential for use as ligament and tendon replacement. Our study shows that a tendon rupture can be augmented with DBM giving intial appropriate mechanical strength suitable for in-vivo use

Aim: To determine the short to mid-term outcome differences between patellar tendon (PT) and hamstring (HS) autograft in anterior cruciate ligament (ACL) reconstructions. Methods: Sixty-five patients undergoing primary ACL reconstruction were randomised to receive either a PT or a quadruple HS autograft. Post operatively patients undertook a standard “accelerated” rehabilitation protocol. Patients were reviewed at four and eight months and then after one, two and three years. Results: Anterior knee pain was significantly more common in the PT group at eight months, and again at two years, but not at other times. Pain on kneeling was significantly greater in the PT group at four months and this difference persisted at three years. There was a significantly greater incidence of effusion in the PT group at eight months. Extension deficits were significantly greater in the PT group at eight months and this continued unchanged at three years. Active flexion deficits were significantly greater in the hamstring group at one and two years but not at three years. KT-1000 side to side differences in anterior knee laxity were significantly greater in the HS group from four months through to three years. There were significantly greater peak quadriceps torque deficits in the PT group at four months and at eight months. Sports activity levels were significantly higher in the PT group at four months but this difference had resolved by eight months. Cincinnati scores were significantly higher in the HS group at one year but not thereafter. There was no difference in IKDC ratings between the two groups. Radiographic femoral tunnel widening was significantly more prevalent and greater in the HS but did not correlate with any clinical differences. Radiographic tunnel widening was present at four months and did not change significantly thereafter. Conclusions: Overall, HS autografts were associated with less morbidity but increased anterior knee laxity and radiographic femoral tunnel widening compared with PT autografts. From a functional point of view, there was no significant difference between the two graft types at three years

Ligamentoplasty resorting to autogenous bone-tendon-bone grafts represents an effective long-lasting remedy to the anterior instability of the knee. If this indication has proved effective regarding the stability, the sampling of a piece of the extensor system often brings about a certain morbidity. Various approaches have been advocated concerning the tendinous site: some leave it open, others suture one of the peripheral thirds of the remaining tendon to the other. These various technical choices are likely to alter the morbidity and the patellar level, together with the tissue nature of the site of sampling. The purpose of this study was to assess the effect of the suture of the site of sampling on the patellar level, after a ligament plastic surgery resorting to a bone-tendon-bone graft. To this end, a group of 40 patients whose tendinous site of sampling had been left open was compared to another group of patients whose peripheral thirds of the remaining patellar tendon had been sutured one to the other. The patellar level was assessed with Caton’s, Black-burne’s and Insall and Salvati’s methods on x-rays first taken before and then 6 months after the operation. To analyse the results, we resorted to the reduced gap method and the Student-Fisher one for the comparison between quantitative and qualitative variables, and to the correlation coefficient method for the comparison between quantitative variables. The post-operative values of Caton’s, Blackburne’s and Insall and Salvati’s indexes were respectively 1.002, 0.844, and 1.188 for patients whose patellar tendon had been left open, and 1.023, 0.882, and 1.184 for patients whose tendinous edges had been sutured up. The discrepancy between those values had no statistical significance. Suturing the site of sampling in a bone-tendon-bone ligament plastic surgery has no effect on the patellar level

We have reviewed 40 patients after replacement of a ruptured anterior cruciate ligament with a free graft of the medial third of the patellar tendon, combining this in 17 of the cases with a MacIntosh extra-articular tenodesis. The average age of the patients at operation was 25.4 years; instability of the knee had been present for 1.5 to 9 years, and the mean follow-up was 2.9 years. The results, assessed on subjective stability, were good in 29 patients, over half being able to return to their original sport, and fair in eight. The technique of operation for free patellar tendon grafting is described in detail and the indications for this and for an additional MacIntosh tenodesis are discussed

At the time of publication sixty-three additional patients have been fitted with the patellar tendon bearing prosthesis. Twenty of these were new amputees, and forty-three were old amputees who had previously worn a conventional limb. Of this group, nine were considered failures. The contra-indications for fitting now include: 1) coincident knee derangement such as cruciate or collateral ligament laxity (the trauma that causes the amputation often produces knee injuries as well; in this event the side irons of the conventional prosthesis help to support the knee); 2) scars in the popliteal fossa, such as those produced by exploration of the popliteal vessels; 3) marked variation in stump size such as in rapidly growing children or obese people; and 4) labourers obliged to work on rough ground, which places additional strain on the knee

Introduction and Aims: Some authors have suggested that, in females, the results of ACL reconstruction using hamstring tendon (HS) grafts are inferior to those using patellar tendon (PT) grafts, while others have suggested that HS grafts may be preferable. This study compared the mid-term results of ACL reconstruction in females using both graft types. Method: Sixty-six females who had undergone primary ACL reconstruction using either HS (n=43) or PT autograft (n=22) were evaluated at a mean 3.7 years follow-up (range 2.6–5.5). All procedures were performed by the same experienced knee surgeon using an arthroscopically assisted, single-incision technique, with Endobutton femoral fixation and interference screw tibial fixation. The same rapid rehabilitation protocol (immediate full extension and weight-bearing; no brace) was used for all patients. Assessment was performed by an independent orthopaedic surgeon and included IKDC 2000, SF-36 and Cincinatti Sports Activity scores and measurements of anterior knee pain (AKP), kneeling pain and anterior knee laxity (KT-1000). Results: The overall results in both groups were good. One PT patient sustained a traumatic graft rupture. The HS patients had higher Cincinnati Sports Activity Scores (HS: 83 vs. PT: 72, p< 0.05), but there was no difference in IKDC subjective scores (HS: 89.6 vs. PT: 85.7). For the SF-36, the HS group scored significantly higher on Physical Functioning (HS: 95.4 vs. PT: 89.8, p< 0.01) and General Health subscales (HS: 87.5 vs. PT: 78.4, p< 0.05), but there were no differences for the other subscales. Although there was no significant difference in AKP between the two groups (HS: 1.3/10 vs. PT: 1.7), there was a significantly greater mean kneeling pain in the PT group (PT: 4.0/10 vs. HS: 1.3, p< 0.001). There was no difference between the groups in side to side difference in anterior knee laxity at 134N (HS: 1.7mm vs. PT: 1.8mm). Seventy percent HS and 71% PT patients had a difference of < 3mm, with all remaining patients having 3–5mm difference. There was no difference in terms of overall IKDC knee examination grade, but the HS group had a lesser (hyper)extension deficit (HS: 1.0° vs. PT: 1.8°, p< 0.05). Conclusion: Both PT and HS ACL reconstructions appear to provide satisfactory results in females, but HS grafts are associated with fewer symptoms, a greater return to pre-injury level of activity and higher quality of life scores

We performed MRI on 16 patients who had had reconstruction of the anterior cruciate ligament (ACL) with a mid-third bone-patellar-tendon-bone autograft. Our aim was to assess the tendon and the site of its insertion at an average of seven years after the original operation. In four of these patients biopsies were taken from the donor site when they had revision of their original operation. MRI showed reconstitution of the tendon into the patellar defect with no evidence of bone formation. Six patients had a persistent defect in the patellar tendon itself. Histological examination of the biopsies of the donor site showed an indirect pattern of insertion with absence of the normal fibrocartilage zone. These morphological changes may adversely affect the biomechanical properties of the healed donor site and we suggest that another graft taken from this site may not be suitable for use in a further operation for reconstruction of the ACL

Purpose: Free patellar tendon plasty is classically used for the treatment of chronic anterior instability of the knee. Good functional results may however be compromised by invalidating anterior pain. The purpose of this randomised trial was to obtain a prospective comparison of outcome after hamstring plasty or patellar tendon plasty. Material and methods: One hundred patients with an isolated tear of the anterior cruciate ligament were included in the study between May 1998 and 2001. Exclusion criteria were history of fracture, grade II laxity, and tear of the contralateral ACL. Patients were assigned to one of the treatment arms in random order in the operating room: Group A: arthroscopic free patellar tendon-bone graft; Group B: arthroscopic free four-strand hamstring graft. Two metal interference screws were used for fixation in all cases. The Aglietti method was used to calculate the position of the bore holes in all cases. The same rehabilitation protocol, in the same centre, was applied in all cases. The two groups were comparable for epidemiological, clinical, radiological, and instrumental laxity (KT1000®) data. IKDC criteria, activity level (sports), and instrumental measurement of laxity (KT1000® Medtronic) were used to assess outcome. Differences were considered significant for p < 0.05. Results: At mean follow-up (24 months, range 6 – 38) groups A and B were not significantly different for delay to resumed sports activity at the initial level, motion, clinical examination of ligaments, IKDC global score, and radiological evolution. At six months, 30% of the patients in group A complained of anterior pain; 20% of the patients still complained of pain at one year. In group B, femoropatellar pain or pain at the harvesting site was reported by 8% of the patients at six months and 4% at one year (p = 0.0005). These differences were no longer present at two years. The instrumental differential laxity was 0.66±1.1 mm in group A and 1±1.5 mm in group B (p =0.20). Two repeated trauma-induced tears were observed in group B. Conclusion: The preliminary results of this prospective randomised trial confirm the low morbidity of the harvesting site for hamstring grafts and the reliable stability of hamstring repair of isolated ACL laxity. A longer follow-up is however needed for long-term validation, particular concerning secondary distension of hamstring grafts as is frequently reported in the literature and which we have also observed in certain patients treated before this series

In the last few years the number of women who practise sport activities has substantially increased and this has led to an increase in the incidence of ACL tear in females. The aim of this study is to assess outcome differences at a minimum 3-year follow-up after ACL reconstruction in women using either a patellar tendon (BPTB) or a quadrupled-looped hamstring (DSTG) autograft fixed with modern devices. Fifty women with a chronic, isolated ACL tear were randomised to receive a DSTG or BPTB graft for ACL reconstruction. Both groups were comparable as to age, injury-surgery, activity level, meniscal tears, surgical technique and reabilitation. All patients were prospectively evaluated by an independent observer using the IKDC form, the FKSAKP Score, the KT-1000 arthrometer and the Cybex NORM dynamometer. A radiographic study was performed to investigate tunnel widening. All but two patients were satisfied with the reconstruction. The average side-to-side difference in anterior tibial translation was 2.4 mm in the BPTB group and 2.5 mm in the DSTG group. The final result was A (normal knee) in 56% and in 60% of the BPTB and the DSTG knees, respectively. A failure (4%) was present in each group. Muscle strength deficits at 60°/s, 120°/s and 180°/s were within 10% for extensors and within 5% for flex-ors in both groups. No statistically significant differences were found in terms of subjective satisfaction, objective evaluation, knee stability and muscle strength recovery. The BPTB group showed a higher incidence of postoperative kneeling discomfort (p< 0.05) and a larger area of decreased skin sensitivity (p< 0.001). The DSTG group showed a higher incidence of femoral tunnel widening (p=0.02). Using strong and stiff fixation devices, ACL reconstruction in women is not influenced by the graft choice

Purpose of the study: The debate continues on the appropriate tendon to use for anterior cruciate ligament (ACL) reconstruction. There are few comparative data on the different types of grafting material. We propose a retrospective analysis of bilateral ACL reconstruction where a patellar tendon (PT) and hamstring tendons were used in the same patient. Material and methods: This was a phase IV trial. From December 1992 through March 2003, ACL reconstructions of both knees were performed in 46 consecutive patients using the PT for one side and hamstring grafts for the other. Follow-up was at least two years for 38 patients. There was no difference between the knees prior to reconstruction. The postoperative protocol was the same for both knees. The Lysholm Knee Score and the IKDC scores as well as KT1000 arthrometry were recorded. Results: There was no difference between the two sides for laxity (KT1000) or resumed sports activity. Postoperative pain, loss of extension, joint stiffness, and anterior pain were greater on the PT reconstruction side. All patients except two preferred the hamstring reconstruction. Conclusion: The results of this study show that the two types of reconstruction are equivalent in terms of objective outcome but that the subjective assessment favors hamstring reconstruction

Purpose: The aim of this study was to document donor site problems one year after anterior cruciate ligament (ACL) reconstruction and to compare the differencies between hamstring and patellar tendon autografts. Materilas and Methods: Sixty-four patients undergoing primary arthroscopically ACL reconstruction were randomized to have a central third bone patellar tendon bone (PT) autograft (30 patients) or a doubled semiten-dinosus/doubled gracilis (HS) autograft (34 patients). The postoperative rehabilitation regimen was identical for both groups. All patients were examined one year postoperatively. Objective parameters evaluated included pre and postoperative IKDC and Lysholm score, side-to-side KT-1000 maximum-manual arthrometer differences. The Shelbourne score was used to evaluate anterior knee symptoms. Loss of sensitivity in the anterior knee region postoperatively as well as scar sensitivity were also recorded. Results: Three patients (10%) in the PT group had anterior knee symptoms while only one (3%) in the HS group. The mean Shelbourne score was 98 for the HS group and 93 for the PT group but this was not statistically significant. However, 8 pateints (23%) had disturbed sensitivity in the anterior knee region in the HS group, but none in the PT group and this was statistically significant (p< 0.005). Scar sensitivity was present in 3 patients (10%) in the PT group and in one (3%) in the HS group. No differencies were found postoperatively between the groups regarding IKDC, Lysholm score and side-to-side KT-1000 measurements. Conclusions: Although,notstatisticallysignificantpatients in the PT group had more anterior knee symptoms and scar sensitivity, one year postoperatively. In contrast, harvesting of hamstring tendons produces significantly more sensory nerve complications in the anterior knee region than harvesting the middle third of patellar tendon. Both grafts seem to improve equally patients’ performance

This investigation of elite male collegiate basketball players aims to determine 1) the change in 3D dynamic functional variables across a single season and 2) correlate cross-season changes in functional variables with changes in clinical and quantitative ultrasound measures. Eleven male college basketball players (mean age 19, range 18–21 years) from a single team underwent baseline patellar tendon shear wave (SW) elastography and dynamic function at the start of the season (Visit1) and at a late-season time point (Visit2). Players reported their VISA-P scores every two weeks across their 24-week season. Each athlete performed a box-ground-box jump five times while 3D lower extremity kinematic and kinetic variables were collected. Functional measures included for landing (LAND) and take-off (TOFF) phases: knee valgus angle, valgus torque, and peak limb force. Knee valgus angular impulse and ground contact time were also measured. Paired t-tests and Pearson correlation coefficients (r) compared Visit1 and Visit2 variables and assessed the strength of linear dependency, respectively. The mean change in VISA-P score was 15.18 (+/-8.55). No functional variables were different across the season. Clinical, quantitative ultrasound and functional variables were moderately correlated with take-off valgus moment, landing force, take-off force and contact time. Other correlations were low (< 0.4). Our analyses have shown moderate correlations between important clinical, quantitative imaging and function measurements. These correlations reflect the changes that occur between relevant time points and which relate internal structure and external function

Abstract

Introduction. The low-contact stress (LCS) knee prosthesis is a mobile-bearing design with modifications to the tibial component that allow for meniscal-bearing (MB) or rotating-platform (RP). The MB design had nonconstrained anteroposterior and rotational movement, and the RP design has only nonconstrained rotational movement. The anterior soft tissues, including patellar tendon (PT), prevent anterior dislocation of the MB. The PT may consistently be exposed to overstressing. Therefore, we hypothesized that the PT thickness and width in MB prosthesis revealed more morphological changes than those of RP prosthesis due to degeneration of the PT induced by much mechanical stress of the MB movement. To confirm this hypothesis, we analyze the PT thickness and width induced by mobile-bearing inserts. Objectives. Sixty LCS prostheses in 30 patients were analyzed. The average follow-up time was 61 months. MB prosthesis was used on one side of the knee and RP prosthesis was used on the contralateral side of the knee. All patients were chosen from group with no clinical complication, and all had achieved passive full extension and at least 90°of flexion. The average Hospital for Special Surgery Score was 94.6 ± 2.7. Methods. We measured the thickness and width of PT at joint line level, which were confirmed by sagittal section using ultrasound in knee extension between MB and RP design prosthesis. Results. The mean thickness of PT was 4.7 mm (1.2) with MB and 4.7 mm (1.0) with RP design prosthesis. The mean width of PT was 30.6 mm (3.2) with MB and 31.3 mm (3.5) with RP design prosthesis. No significant differences were found between both groups. Conclusion. The current results showed that the PT thickness and width in MB prosthesis did not reveal more morphological changes than those of RP prosthesis due to degeneration of the PT induced by much mechanical stress of the MB movement. The possible reasons are the following: (1) We did not remove infra-patellar fat pad, which might play shock absorber of mechanical stress from MB, and prevent from significant degeneration of PT, (2) MB inserts did not stimulate the middle of the PT directly, unlike LCS A/P-Glide inserts, and might come into contact with the both ends of the PT and (3) MB inserts did not move so as to cause degeneration in the PT

The aim of this longitudinal study is to compare the clinical outcomes of endoscopic ACL reconstruction with either a 4-strand HT or PT autograft over a 5-year period. 90 patients with isolated ACL rupture received PT autograft and 90 received HT autograft were studied annually for 5 years. Assessment included the IKDC Knee Ligament Evaluation, KT1000, Lysholm Knee Score, thigh atrophy, kneeling pain, hamstring pain and radiographs. The median Lysholm Knee Score was 96 for the PT group and 95 for the HT group. No significant difference was found for subjective knee function, overall IKDC assessment, Xray findings, manual ligament KT1000 instrumented testing, graft rupture or contralateral ACL rupture. There was an increasing incidence of fixed flex-ion deformity seen in the PT group. There was no difference in the requirement for subsequent surgery. The incidence of kneeling pain at 5 years was significantly higher in the PT group. Endoscopic reconstruction of the ACL utilizing either autograft can restore knee stability and is menisco protective despite a high level of sporting activity. We did find a worrying trend towards an increasing incidence of fixed flexion deformity with time in the patellar tendon group. Kneeling pain also remains a persistent problem in this subgroup

Purpose: The optimal autograft choice for ACL reconstruction remains controversial. Twelve recently published reviews comparing Patellar Tendon (PT) to Hamstring Tendon (HT) autografts in ACL reconstruction vary in their methodology, quality and application of sensitivity analyses. The present review and meta-analysis follows the rigorous methodology of the Cochrane Collaboration of Systematic Reviews and includes more recent trials that utilize modern surgical techniques and concealed randomization. Method: Randomized Clinical Trials (RCT) and Quasi-randomized Trials (QRCT) with a minimum 2-year follow-up comparing PT with HT autografts in patients undergoing primary ACL reconstruction were included. Non-English articles were professionally translated. Four electronic databases were searched from 1969-present. Bibliographies and proceedings of major orthopaedic meetings were handsearched. Two teams of investigators independently reviewed all citations, selected relevant studies, extracted the data and assigned quality scores. Consensus was achieved within and between each team for all stages of the review process. Results: Three hundred and twenty-six citations were originally identified with the search criteria. Following rigorous review, 26 relevant studies were identified. Nine were excluded due to missing information, inadequate follow-up, ongoing trials or low quality scores, leaving 17 studies included in the final analysis. Outcomes related to stability (Lachman test, instrumented laxity, and pivot shift) showed trends towards improved stability with PT reconstruction. When QRCTs were excluded there was a significant difference favoring PT reconstructions only with respect to the pivot shift test. All other outcomes were similar between the PT and HT reconstructions including IKDC categories, anterior knee pain (trend in favor of HT), re-rupture rate, and activity levels. No information was available to distinguish between the outcome of acute and chronic reconstructions, long term information or validated patient based outcomes. Conclusion: The current literature fails to demonstrate significant differences in multiple outcomes comparing PT to HT reconstruction of the ACL. The overall quality of trials is questionable and fails to use validated patient based outcomes or sufficiently long-term results to assess the development of osteoarthritis

We performed a clinical, instrumental and radiographic study on a highly homogeneous series of 100 consecutive patients with unilateral ACL lesion at 7 years of minimum follow up, alternatively assigned to a single bundle reconstruction using patellar tendon (PT) or to a double bundle reconstruction using hamstrings (DB). Mean Tegner score was 4,8 for PT and 6,5 for DB (p=0,0005). Time for sport resumption was 6,6 months for PT and 3,8 months for DB (p=0,0052). There were no significative differences between the two groups regarding range of motion and functional subjective self-evaluation. Mean anterior displacement at instrumental evaluation performed with KT2000 showed no significative differences between the two groups. Objective clinical evaluation with IKDC was superior for DB group (A=86,5%; B=13,5%) respect to PT group (A=18,7%; B=75%; C=6,3%) (p< 0,0001). We found no differences regarding anterior knee pain between and Ahlback radiographic score the two groups and we have observed no recurrence of instability after surgical treatment. Double bundle ACL reconstruction with hamstrings has showed higher results respect to single bundle ACL reconstruction with patellar tendon in terms of Tegner score, IKDC, time for sport resumption

Purpose of the study: The objective was to compare the results of ligamentoplasties with two commonly used grafts, hamstring and patellar tendon. This was a prospective randomized study. Material and methods: Between January 2001 and June 2004, 98 patients with an acute or chronic anterior cruciate ligament (ACL) tear with joint instability were included in this randomized study for arthroscopic repair. Patients were randomized to the patellar or hamstring arm. Clinical assessment was based on laxity, IKDC score, Lyscholm score, pain visual analog scale (VAS), midthigh thickness and isokinetic assessment at three months. Measurements were recorded preoperatively and at 1, 3, 6 weeks and 3, 6, and 12 months. Results: The two groups were comparable regarding gender, morphotype, associated lesions, and activity level. There was no difference in operative time or in recovery of complete extension. Anterior laxity was the same in the two groups. The isokinetic deficit appeared to be greater in the bone-tendon-bone group at three months. The IKDC and Lysholm scores were not significantly different at six and twelve months. Harvesting site morbidity was more pronounced in the bone-tendon-bone group. Conclusion: The two techniques provide good results. The bone-tendon-bone technique appears to cause greater harvesting site morbidity. While the isokinetic results appear to be better in the hamstring group, the measurements of laxity and recovery of stability did not show any difference