Risk Of Anterior Knee Pain Research Articles

Biomechanical and biological factors of sexual dimorphism in anterior knee pain: Current concepts

Female gender is one of the commonly mentioned risk factors for anterior knee pain (AKP), among a spectrum of other factors including anatomical, biomechanical, hormonal, behavioral and psychological elements contributing to its development. Despite the focus on individual risk factors, there's a notable gap in comprehending how gender influences and interacts with other risk factors. The objective of this review was to identify and emphasize the connections between these interactions, gender-related risk factors for AKP, and the potential mechanisms that explain their associations with other risk factors, aiming to aid in the creation of precise prevention and treatment approaches. Gender influences the majority of risk factors for AKP, including anatomical, biomechanical, hormonal, behavioral and psychological factors. Women have on average smaller patellae, higher patellofemoral cartilage stress and for AKP, disadvantageous trochlear morphology, ligament and muscle composition and unfavorable neuromuscular control pattern. In contrast, men show on average an increased ability to strengthen their hip external rotators, which are both protective against AKP. Particularly in kinetic and kinematic analysis, men have been shown to have a distinctly different risk factor profile than women. Sex hormones may also play a role in the risk of AKP, with estrogen potentially influencing ligamentous laxity, increasing midfoot loading and affecting neuromuscular control of the lower extremities and testosterone positively affecting muscle mass and strength. The higher incidence of AKP in women is likely due to a combination of slightly increased risk factors. Although all risk factors can be present in both men and women and the holistic evaluation of each individual's risk factor composition is imperative regardless of gender, knowing distinctive risk factors may help with focused evaluation, treatment and implementing preventive measures of AKP.

Patient Decision Making in Anterior Cruciate Ligament Reconstruction: A Discrete Choice Experiment Examining Graft Preference.

Bone-patellar tendon-bone (BTB) and hamstring autografts are the most common grafts used for anterior cruciate ligament (ACL) reconstruction. Patient preferences should be accounted for as a part of shared decision making. The purpose of this study was to perform a discrete choice experiment that evaluated patient preferences toward ACL autografts. We hypothesized that there would be no difference in patient preferences between groups. Cross-sectional study. Patients aged 18 to 25 years who underwent shoulder arthroscopy at a single institution between 2013 and 2019 were included in the study as a proxy for healthy controls. Patients with a history of ACL tear were excluded. A discrete choice experiment was developed from a literature search and used the following data points as they pertain to BTB or hamstring autograft: risk of developing a significant complication, return-to-play rate, risk of anterior knee pain with kneeling, and risk of additional surgery due to graft failure. Included patients completed a custom survey in which they were asked to choose between "surgery A" (hamstring) and "surgery B" (BTB). A total of 107 participants were included in the analysis. Of these participants, 39 (36.5%) chose surgery A (hamstring) and 68 (63.6%) chose surgery B (BTB). When comparing the hamstring group with the BTB group, there was no significant difference in age, sex, body mass index, race, level of education, or employment status. However, 80.5% of self-reported athletes preferred BTB (P = .008). When controlling for age, sex, and body mass index, patients in the BTB group were more likely to rate return to sport (risk ratio [RR] = 1.49 [95% CI, 1.18-1.98]; P = .001) and the risk of requiring additional surgery due to graft failure (RR = 1.26 [95% CI, 1.02-1.58]; P = .037) as highly important. Conversely, they were less likely than patients in the hamstring group to rate pain while kneeling (RR = 0.65 [95% CI, 0.98-1.05]; P < .001) and complication risk (RR = 0.75 [95% CI, 0.59-0.94]; P = .013) as important. The study hypothesis was rejected, as patient values did affect ACL graft choice preference. Utilizing patient-selected values in a quantifiable way can benefit the shared decision-making process before ACL reconstruction.

Rehabilitation of anterior knee pain in the pregnant athlete: Considerations and modifications by trimester

BackgroundAnterior knee pain is a common symptom many females experience during pregnancy. There are several musculoskeletal changes that occur in anatomy and physiology throughout the course of pregnancy that impact the lower extremity kinetic chain. Pregnant athletes, recreational through competitive, who attempt to maintain a high activity level through each trimester may be at increased risk for anterior knee pain due to a greater demand for lumbopelvic and hip stabilization. Clinical questionWhat are the evidence-driven rehabilitation guidelines and specific modifications needed to treat anterior knee pain in the female athlete during each trimester of pregnancy? Key resultsWe aim to provide an overview of rehabilitation treatment guidelines for pregnant females with anterior knee pain, presenting specific physiological changes and rationale for modifications, discussed by trimester. We recommend our program be conducted under the supervision of a physical therapist working closely with the athlete's obstetrics and sports medicine team. Clinical applicationThe number of women who are active during pregnancy is increasing. We provide an overview of the guidelines and considerations for treating women with anterior knee pain during a healthy and uneventful pregnancy.

Clinical effectiveness of patellar resurfacing, no resurfacing and selective resurfacing in primary total knee replacement: systematic review and meta-analysis of interventional and observational evidence

BackgroundPatellar resurfacing is optional during total knee replacement (TKR). Some surgeons always resurface the patella, some never resurface, and others selectively resurface. Which resurfacing strategy provides optimal outcomes is unclear. We assessed the effectiveness of patellar resurfacing, no resurfacing, and selective resurfacing in primary TKR.MethodsA systematic review and meta-analysis was performed. MEDLINE, Embase, Web of Science, The Cochrane Library, and bibliographies were searched to November 2021 for randomised-control trials (RCTs) comparing outcomes for two or more resurfacing strategies (resurfacing, no resurfacing, or selective resurfacing) in primary TKR. Observational studies were included if limited or no RCTs existed for resurfacing comparisons. Outcomes assessed were patient reported outcome measures (PROMs), complications, and further surgery. Study-specific relative risks [RR] were aggregated using random-effects models. Quality of the evidence was assessed using GRADE.ResultsWe identified 33 RCTs involving 5,540 TKRs (2,727 = resurfacing, 2,772 = no resurfacing, 41 = selective resurfacing). One trial reported on selective resurfacing. Patellar resurfacing reduced anterior knee pain compared with no resurfacing (RR = 0.65 (95% CI = 0.44–0.96)); there were no significant differences in PROMs. Resurfacing reduced the risk of revision surgery (RR = 0.63, CI = 0.42–0.94) and other complications (RR = 0.54, CI = 0.39–0.74) compared with no resurfacing. Quality of evidence ranged from high to very low. Limited observational evidence (5 studies, TKRs = 215,419) suggested selective resurfacing increased the revision risk (RR = 1.14, CI = 1.05–1.22) compared with resurfacing. Compared with no resurfacing, selective resurfacing had a higher risk of pain (RR = 1.25, CI = 1.04–1.50) and lower risk of revision (RR = 0.92, CI = 0.85–0.99).ConclusionsLevel 1 evidence supports TKR with patellar resurfacing over no resurfacing. Resurfacing has a reduced risk of anterior knee pain, revision surgery, and complications, despite PROMs being comparable. High-quality RCTs involving selective resurfacing, the most common strategy in the UK and other countries, are needed given the limited observational data suggests selective resurfacing may not be effective over other strategies.

Biomechanical research on effects of pseudo-patella baja on stress of patellofemoral joint after total knee arthroplasty

To investigate biomechanical effects of pseudo-patella baja on stress of patellofemoral joint after total knee arthroplasty (TKA) by using finite element analysis (FEA). A series of CT and MRI of the left knee joint of two healthy volunteers and three-dimensional (3D) scanned data of TKA prosthesis were taken, and the 3D models of knee before and after TKA were established. The finite element model of pseudo-patella baja, normal patella, and alta patella after TKA were constructed by Insall-Salvafi (IS) ratio and Blackburne-Peel (BP) ratio. The load was applied along the direction of quadriceps femoris. After testing the validity of the finite element model, the high contact stress of patellofemoral joint was measured on the von Mise stress nephogram of pseudo-patella baja, normal patella, and alta patella after TKA when the knee flexion was 30°, 60°, and 90°. The average contact area was calculated according to two volunteers' data. On the finite element model of the normal patella after TKA with knee flexion 30°, 475 N pressure was applied along the direction of quadriceps femoris. The contact stress of patellofemoral joint was (1.29±0.41) MPa, which was similar to the results reported previously. The finite element model was valid. The von Mise stress nephogram showed that the stress mainly focused on the medial patellofemoral articular surface during knee flexion, and the contact point gradually moved up with the knee flexion deepened. The stress on the medial and lateral patellofemoral articular surface increased with the knee flexion deepened but decreased with the increase of patellar height. The effects of patellar height and knee flexion on the high contact stress of patellofemoral joint were similar among the finite element models after TKA based on the data of two volunteers. The high contact stress of patellofemoral joint increased with the knee flexion deepened in the same patellar height models ( P<0.05), but decreased with the increase of patellar height in the same knee flexion models ( P<0.05). The high contact stress of patellofemoral joint of pseudo-patella baja model was significantly higher than normal and alta patella models ( P<0.05). The average contact area of patellofemoral joint of pseudo-patella baja was bigger than normal and alta patella models with the knee flexion deepened. The pseudo-patella baja after TKA has an important effect on the biomechanics of patellofemoral joint. Reserving the joint line and avoiding the occurrence of pseudo-patella baja can decrease the risk of anterior knee pain, patellar arthritis, and other complications caused by the increasing of contact stress of patellofemoral joint.

Patellar Tendon Versus 4-Strand Semitendinosus and Gracilis Autografts for Anterior Cruciate Ligament Reconstruction: A Meta-analysis of Randomized Controlled Trials With Mid- to Long-Term Follow-Up

To compare patellar tendon (PT) autografts with 4-strand semitendinosus and gracilis (STG) autografts concerning knee stability, functional outcomes, as well as complications after anterior cruciate ligament (ACL) reconstruction at minimal follow-up of 5 years. A systematic search of the literature was performed in PubMed, Embase, and the Cochrane Library to identify published prospective randomized controlled trials on clinical studies comparing PT autograft and 4-strand STG autografts for ACL reconstruction. The results of the eligible studies were analyzed in terms of knee stability (laxity measurements, Lachman test, and pivot-shift test), functional outcomes (Lysholm score, International Knee Documentation Committee score, Cincinnati score, Tegner score, single-legged hop test, and return to preinjury activity level), and complications (loss of range of motion [ROM], pain, graft re-rupture, revision, and osteoarthritis [OA]). Nine clinical studies with 630 patients (313 PT and 317 STG autografts) met the inclusion criteria. No statistically significant differences were found between the PT and STG group in Lachman test, pivot-shift test, International Knee Documentation Committee score, Cincinnati score, loss of ROM, kneeling pain, graft re-rupture rate, revision rate, and OA rate. The STG group was found with less anterior knee pain (P= .003). There were no clinically significant differences for the outcomes of SSD, Lysholm score, and Tegner score. Except for significantly greater risk of anterior knee pain, PT autograft had comparable results with 4-strand STG autograft in terms of knee stability and functional outcomes after ACL reconstruction with mid- to long-term follow-up. Besides, we found no statistically significant difference in loss of ROM, kneeling pain, graft re-rupture rate, revision rate, and OA change, but these results were underpowered. Level I, meta-analysis of Level I studies.

A Technique Utilizing GraftNet to Fill Graft Donor Sites in Bone-Patellar-Bone Anterior Cruciate Ligament Reconstruction

Anterior knee pain and patella fracture are 2 potential complications of bone-patellar-bone autograft anterior cruciate ligament reconstruction. Techniques have been developed to minimize the risk of these complications, including filling the defects with autologous bone fragments and augmenting with biologic agents. We have developed a technique that uses a graft collection device to collect the autologous bone graft generated during surgery. This graft augments the larger bone graft derived from the bone plugs. This autologous augmentation provides a complete biologic strategy to potentially reduce the risk of anterior knee pain and potential patella fracture.

Prevalence of anterior knee pain after patellar retention total knee arthroplasty: Comparison of patients with rheumatoid arthritis versus primary osteoarthritis

ObjectiveThe aim of this study was to investigate whether there is an increased risk of anterior knee pain (AKP) after total knee arthroplasty (TKA) without patellar resurfacing in patients with rheumatoid arthritis (RA) versus primary osteoarthritis (OA). MethodsThis study was a retrospective review of 388 patients (577 knees) who underwent TKA without patellar resurfacing between 2003 and 2011, with a minimum of 5 years of follow-up. Patients were divided into two groups: Group OA (273 knees of 206 patients; 83 males, 123 females; mean age: 64.4 (47–87) years) and Group RA (304 knees of 182 patients; 92 males, 90 females; mean age: 50.7 (21–72) years). In the clinical evaluation, the knee range of motion (ROM) and several outcome measures such as The Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and International Knee Documentation Committee (IKDC) scores were used preoperatively and at the final follow-up visit. The quality of life was measured using Short Form (SF)-36 MCS and PCS scores. The primary outcome was the frequency and severity of patient-reported AKP. The AKP Scale was used to determine the severity of AKP. ResultsThe IKDC raised from 21.62 (range, 13–29.9) preoperatively to 85.1 (range, 80–88) for group OA and from 21.8 (range, 13–29.9) to 85.2 (range, 81–88) for group RA (p < 0.001). The mean KSS improved from 28.35 (range, 22–38) preoperatively to 90.04 (range, 88–95) for group OA and from 21.9 (range, 18–35) preoperatively to 89.7 (range, 86–95) for group RA. The mean WOMAC increased from 20.61 (range, 17.4–24.2) preoperatively to 95.7 (range, 90.9–97.7) for group OA (p < 0.001) and from 20.2 (range, 16.7–24.2) preoperatively to 95.8 (range, 90.9–98.5) for group RA (p < 0.001). The mean ROM improved from 80.14° (range, 55°–130°) preoperatively to 113.17° (range, 95°–140°) in group OA (P = 0.003) and from 73.4° (range, 10°–130°) to 112.8° (range 90°–140°) in group RA (P = 0.003) postoperatively. The frequency of AKP was 8% in Group OA and 7% in Group RA (p = 0.27). For patients with AKP, the mean AKP Scale was 92.74 (range, 84–98) in Group OA and 93.39 (range, 82–98) in Group RA (p = 0.3). ConclusionAfter TKA without resurfacing the patella, patients with RA were determined to have a similar risk for AKP as those with OA. Level of evidenceLevel III, Therapeutic Study.

Tension band plating of an anterior tibial stress fracture nonunion in an elite athlete, initially treated with intramedullary nailing: a case report

BackgroundLeg pain in athletes is a common condition and is often related to tibial stress fracture. When non-operative treatment fails, the optimal surgical treatment is controversial. The aim of this study was to report a case of tension band plating of an anterior tibial stress fracture nonunion, treated previously with intramedullary nailing. To the best of our knowledge, this is the first reported case in which tension band plating was placed without removing the preexisting intramedullary nail.Case presentationThe tibial shaft is a common location of stress fracture in athletes. Anterior tibial stress fractures are difficult to manage. When conservative treatment fails, intramedullary nailing is the mainstay of treatment. However, nonunion is a serious complication. In our case, a non-united anterior tibial stress fracture, treated with intramedullary nailing, was addressed with the application of a compression prebended plate over the nail in a 23-year-old French man of African origin who is an elite football player. At 3-months postoperatively he was pain free and started light exercises. At 6-months postoperatively, complete radiologic union of the fracture was evident. He was symptom free; he resumed at that time a full training program and he returned to play football at preinjury high competition level.ConclusionsCompression plating is a valuable method of treating non-united anterior tibial stress fractures. We believe that anterior tension band plating is superior to intramedullary nailing in managing anterior tibial stress fractures, not only after failure of intramedullary nailing, but also as a first-line surgical treatment. This technique offers advantages, such as no violation of the extensor mechanism and risk of anterior knee pain, and directly addresses the underlying problem of distraction forces acting on the anterior tibial cortex and compromising fracture healing. Especially in high-level athletes, who cannot tolerate prolonged inactivity, early surgical intervention of anterior tibial stress fractures with tension band plating is a reliable option that can accelerate recovery.

Superior-inferior position of patellar component affects patellofemoral kinematics and contact forces in computer simulation

BackgroundAnterior knee pain has been reported as a major postoperative complication after total knee arthroplasty, which may lead to patient dissatisfaction. Rotational alignment and the medial-lateral position correlate with patellar maltracking, which can cause knee pain postoperatively. However, the superior-inferior position of the patellar component has not been investigated. The purpose of the current study was to investigate the effects of the patellar superior-inferior position on patellofemoral kinematics and kinetics. MethodsSuperior, central, and inferior models with a dome patellar component were constructed. In the superior and inferior models, the position of the patellar component translated superiorly and inferiorly, respectively, by 3mm, relative to the center model. Kinematics of the patellar component, quadriceps force, and patellofemoral contact force were calculated using a computer simulation during a squatting activity in a weight-bearing deep knee bend. FindingsIn the inferior model, the flexion angle, relative to the tibial component, was the greatest among all models. The inferior model showed an 18.0%, 36.5%, and 22.7% increase in the maximum quadriceps force, the maximum medial patellofemoral force, and the maximum lateral patellofemoral force, respectively, compared with the superior model. InterpretationSuperior-inferior positions affected patellofemoral kinematic and kinetics. Surgeons should avoid the inferior position of the patellar component, because the inferior positioned model showed greater quadriceps and patellofemoral force, resulting in a potential risk for anterior knee pain and component loosening.

Anterior Tibial Stress Fractures: Intramedullary Nail vs Anterior Tension Band Plating

Lower extremity stress fractures are common overuse injuries in endurance athletes. Most fractures are low risk and respond well to nonsurgical management involving rest, activity modification, and slow resumption of activities after symptom resolution. However, some high-risk fractures or nonunions warrant surgical intervention to prevent fracture completion and continued symptoms. Anterior stress fractures of the tibial shaft are tension-sided high-risk stress fractures with significant risks of delayed union, nonunion, and fracture propagation. The gold standard surgical treatment has traditionally been antegrade tibial intramedullary nailing. However, the risk of anterior knee pain following intramedullary nail placement has prompted clinicians to seek alternative methods of fixation. Anterior tibial plating with biological augmentation is biomechanically sound in that the plate is placed on the tension side, able to resist tensile stress, and biologically sound in that bone graft may be used to enhance fracture healing. The purpose of this article is to describe the presentation, evaluation, and management of patients with anterior tibial shaft stress fracture. The surgical techniques for intramedullary nail and anterior plating are discussed and illustrated in detail.

Lower extremity rotational deformities and patellofemoral alignment parameters in patients with anterior knee pain.

Anterior knee pain is a common musculoskeletal condition amongst young adult population. Lower extremity structural factors, such as increased femoral anteversion and lateral tibial torsion, may contribute to patellofemoral malalignment and anterior knee pain. The aim of this study was to evaluate the lower extremity structural factors and related patellofemoral alignment parameters that play a role in the aetiology of anterior knee pain. This study involved three groups: patients with unilateral symptomatic knees (n=35), asymptomatic contralateral knees in the same patients and a control group (n=40). All subjects were physically examined, and Q-angles were measured. The lower extremities of all subjects were imaged by a very low-dose CT scan, and the symptomatic knees of patients were compared with their asymptomatic contralateral knees and with the healthy knees of controls regarding femoral anteversion, tibial torsion, sulcus angle, patellar tilt angle and lateral patellar displacement. Regarding the Q-angle, femoral anteversion and lateral tibial torsion, no significant differences were found between the symptomatic and asymptomatic knees, whereas significant differences were found between the symptomatic knees and controls. The symptomatic group demonstrated significantly greater sulcus angle only in 30° of knee flexion than did the controls. Patients with unilateral anterior knee pain may have similar morphology at their contralateral asymptomatic lower extremity, and different morphology compared with healthy controls. Lower extremity rotational deformities may increase the risk of anterior knee pain; however, these deformities alone are not sufficient to cause knee pain, and may be predisposing factor rather than a direct aetiology. Diagnostic study, Level III.

Tension Band Plating for Chronic Anterior Tibial Stress Fractures in High-Performance Athletes

Background: Anterior tibial stress fractures are associated with high rates of delayed union and nonunion, which can be particularly devastating to a professional athlete who requires rapid return to competition. Current surgical treatment strategies include intramedullary nailing, which has satisfactory rates of fracture union but an associated risk of anterior knee pain. Anterior tension band plating is a biomechanically sound alternative treatment for these fractures. Hypothesis: Tension band plating of chronic anterior tibial stress fractures leads to rapid healing and return to physical activity and avoids the anterior knee pain associated with intramedullary nailing. Study Design: Case series; Level of evidence, 4. Methods: Between 2001 and 2013, there were 13 chronic anterior tibial stress fractures in 12 professional or collegiate athletes who underwent tension band plating after failing nonoperative management. Patient charts were retrospectively reviewed for demographics, injury history, and surgical details. Radiographs were used to assess time to osseous union. Follow-up notes and phone interviews were used to determine follow-up time, return to training time, and whether the patient was able to return to competition. Results: Cases included 13 stress fractures in 12 patients (9 females, 3 males). Five patients were track-and-field athletes, 4 patients played basketball, 2 patients played volleyball, and 1 was a ballet dancer. Five patients were Division I collegiate athletes and 7 were professional or Olympic athletes. Average age at time of surgery was 23.6 years (range, 20-32 years). Osseous union occurred on average at 9.6 weeks (range, 5.3-16.9 weeks) after surgery. Patients returned to training on average at 11.1 weeks (range, 5.7-20 weeks). Ninety-two percent (12/13) eventually returned to preinjury competition levels. Thirty-eight percent (5/13) underwent removal of hardware for plate prominence. There was no incidence of infection or nonunion. Conclusion: Anterior tension band plating for chronic tibial stress fractures provides a reliable alternative to intramedullary nailing with excellent results. Compression plating avoids the anterior knee pain associated with intramedullary nailing but may result in symptomatic hardware requiring subsequent removal.

Tension Band Plating of a Nonunion Anterior Tibial Stress Fracture in an Athlete

The authors present a rare technique of tension band plating of the anterior tibia in the setting of a nonunion stress fracture. Surgical management with an intramedullary nail is a viable and proven option for treating such injuries. However, in treating elite athletes, legitimate concerns exist regarding the surgical disruption of the extensor mechanism and the risk of anterior knee pain associated with intramedullary nail use. The described surgical technique demonstrates the use of tension band plating as an effective treatment of delayed union and nonunion anterior tibial stress fractures in athletes without the potential risks of intramedullary nail insertion.

Secondary Resurfacing of the Patella After Primary Total Knee Arthroplasty: Does the Anterior Knee Pain Resolve?

Although it has been shown that the risk of anterior knee pain is greater in patients with nonresurfaced patellae, it is not exactly clear whether the pain would resolve with secondary resurfacing of the patella. Thirty-nine patients (41 knees) underwent secondary patellar resurfacing between January 2001 and January 2007. The mean age was 66 years. The mean body mass index was 29.2 kg/m 2. The average time from primary total knee arthroplasty to resurfacing procedure was 29 months. The mean follow-up was 54 months. Anterior knee pain was the indication for secondary resurfacing in all patients. Although the clinical and functional knee scores improved significantly for whole cohort, 8 patients (8 knees) were dissatisfied with the outcome of surgery. This study highlights that secondary resurfacing is not an always rewarding procedure and patients need to be consulted appropriately with regard to the outcome.

Secondary Resurfacing of the Patella after Primary TKA: Does the Anterior Knee Pain Resolve?

s e37 Paper #34 Secondary Resurfacing of the Patella after Primary TKA: Does the Anterior Knee Pain Resolve? Richard H. Rothman, MD, PhD, Javad Parvizi, MD, FRCS, S.M. Javad Mortazavi, MD, Chaitu Devulapalli, BS, Peter F. Sharkey, MD, William J. Hozack, MD Introduction: The issue of patellar resurfacing during TKA still continues to be debated. Although it has been shown that the risk of anterior knee pain (AKP) is greater in patients with non-resurfaced patellae, it is not exactly clear whether the pain would resolve with secondary resurfacing of the patella. The purpose of this study was to determine the outcome of secondary patellar resurfacing after primary TKA. Material and Methods: The computerized database was used to identify all patients undergoing secondary resurfacing or patella after TKA at our institution. Forty-one secondary patellar resurfacing were carried out on 39 patients between August 2000 and January 2007. The mean age of patients was 68 years (range, 43-84). The mean BMI of patients was 29.2 (22.6-52.7). The average time from primary TKA to resurfacing procedure was 28.8 months (range, 4.4-79.1). The mean follow-up was 48.1 months (range, 12-89.7). Result: Anterior knee pain was the indication for secondary resurfacing. The mean clinical knee society score (KSS) improved from 66 to 83 points and the mean functional KSS from 48.2 to 60.3 (P = .0002). The knee pain also significantly improved from a mean of 19.7 to 36.7 postoperatively (P = .0001). Nine patients (22%) were dissatisfied with the outcome of surgery; 6 of them needed further reoperations. Conclusion: Our data showed that the overall pain significantly decreased after secondary patellar resurfacing, yet a considerable number of patients were unsatisfied with the result of second surgery. This highlights the fact that anterior knee pain after TKA could have multiple etiologies and non-resurfaced patella is not the sole cause of this problem. Given our modest success with secondary resurfacing, patients undergoing this procedure should be counseled appropriately.

Mini-incision Patellar Tendon Harvest and Anterior Cruciate Ligament Reconstruction Using Critical Bony Landmarks

Graft choice remains an area of contention in anterior cruciate ligament reconstruction. Poorer cosmetic results and anterior knee pain remain a problem in the use of autologous patellar tendon grafts despite excellent clinical results when compared with autologous hamstring tendon grafts. Using a 2-incision technique to harvest the patellar tendon grafts has been shown to decrease the risk of anterior knee pain to a level comparable to hamstring tendon grafts. Proper graft tunnel placement and orientation also remain controversial with several recent researchers arguing the ability to perform an anatomic reconstruction using a conventional endoscopic transtibial technique. We will describe a relatively simple and cosmetically acceptable 2-incision technique for harvesting a bone-tendon-bone graft. In addition, we will describe the bony landmarks that should be used to ensure proper anatomic graft placement and the appropriate angles that need to be used for the tibial tunnel to drill the femoral tunnel in an anatomic position and carry out a successful endoscopic transtibial tunnel anterior cruciate ligament reconstruction.

Resurfacing versus nonresurfacing the patella in total knee arthroplasty: a critical appraisal of the available evidence

A systematic literature search for evidences comparing treatment effect and harm of resurfacing versus nonresurfacing the patella in total knee arthroplasty was conducted and yielded five meta-analysis (MA), one systematic review (SR) and six randomized controlled trials not included in previous MAs/SR. The evidence suggests that patellar resurfacing would reduce the risk of anterior knee pain, as well as the risk of patella-related reoperation. Furthermore, patients not undergoing patella resurfacing would experience more knee pain during stair climbing and be less satisfied with surgery. No significant difference in range of motion can be expected with or without patellar resurfacing. Importantly, methodological limitations were observed in all retrieved studies and evidences about potential adverse events related to patellar resurfacing are presently undetermined.

Consultation With the Specialist: Patellofemoral Conditions in Childhood

1. Theodore J. Ganley, MD* 2. Rebecca L. Gaugles* 3. Leslie A. Moroz* 1. *Division of Orthopaedic Surgery, The Children’s Hospital of Philadelphia, Philadelphia, Pa After completing this article, readers should be able to: 1. Describe the signs, symptoms, and risk factors related to patellofemoral instability and pain. 2. Discuss the elements of physical examination and the radiographic features that can help diagnose these conditions. 3. Assess the risk for recurrent instability and pain. 4. Provide patients with an overview of treatment options. Patellofemoral instability and patellofemoral pain are seen commonly in the outpatient setting. An understanding of knee anatomy and accurate interpretation of clinical findings are necessary to evaluate and manage patellofemoral pain and instability properly and to help young patients return safely to sports. In this article, we discuss how to distinguish patellofemoral instability from patellofemoral pain and offer our approach to managing these conditions. Patients who have increased hip internal rotation, lower leg external rotation, knock knee alignment, flat foot, tight hamstrings, tight heel cords, and poor quadriceps muscle tone are at increased risk for anterior knee pain. This condition is referred to as patellofemoral or anterior knee pain syndrome. The previous term, chondromalacia patella, has fallen out of favor because it refers only to the anatomic changes of the undersurface of the patella and not to the soft tissue or afferent and efferent pain fibers. The physical examination for this condition follows the general protocol for assessment of knee pain. All patients should be evaluated to be sure that they have level shoulders and pelvis without evidence of spinal asymmetry. An observation of walking and running can help rule out quadriceps atrophy and identify painful or antalgic gait patterns as well as foot progression angles that show intoeing or out-toeing. Patients are evaluated prone and supine to ensure that hip, knee, and ankle strength and range of motion are symmetric. A standing evaluation checks for evidence of malalignment, including genu valgum, calcaneovalgus, and pes planus. …

Etiologic factors associated with anterior knee pain in distance runners.

The objectives of this study were 1) to examine the differences between a noninjured (C) cohort of runners (N = 70) and runners afflicted with anterior knee pain (AKP) according to selected training, anthropometric, rearfoot motion, ground reaction force, and muscular strength and endurance variables; 2) to explore multivariate relationships among these measures in the well and injured groups; and 3) to develop specific hypotheses concerning risk factors for injury that will later be tested in a prospective clinical study. High speed videography (200 frames x s(-1)), a force platform (500 Hz), and a Cybex II+ isokinetic dynamometer were used to assess rearfoot motion, ground reaction forces, and knee muscular strength and endurance, respectively. A linear discriminant function was performed on each of the five categories of variables and revealed 19 significant (P < or = 0.05) predictors. These variables were then combined and a final discriminant function analysis was performed. Pronation through the first 10% of stance, arch index, shoe mileage, and extension peak torque were the best overall (P < or = 0.05) predictors. The AKP group had smaller mean values on all four significant predictors. With the exception of shoe mileage, which is likely a response to rather than a risk factor for AKP, these results should prove useful to clinicians in identifying runners at risk for anterior knee pain.