Nanohydroxyapatite promotes the healing process in open-wedge high tibial osteotomy: A CT study.

BACKGROUND: The aim of this prospective and randomized study was to evaluate the effectiveness of adding nanohydroxyapatite (NHA) to heterologous bone graft in open wedge high tibial osteotomy (OWHTO) by measuring the bone density of the tibial osteotomy gap. METHODS: Twenty-seven patients (26 knees) were operated by OWHTO and randomly divided into two groups: pure graft group, in which the osteotomy gap was filled with only heterologous bone graft; nanohydroxyapatite group, in which the osteotomy gap was filled with heterologous bone graft and NHA. All patients underwent computed tomography (CT) examination within one week after operation (Time 0), and after two months (Time 1) and 12months (Time 2). CT volume acquired Hounsfield Units (HU) were calculated and the mean value of bone density on three planes was measured. RESULTS: At Time 0, the mineral density of the nanohydroxyapatite group appeared significantly higher compared with the pure graft group, due to the presence of NHA. At Time 1, the mineral density of the nanohydroxyapatite group had decreased relative to Time 0, while in the pure graft group it remained unchanged. At Time 2, the mineral density in the nanohydroxyapatite group had further decreased, reaching values close to the mineral density of normal bone. In contrast, in the pure graft group the mineral density had increased, probably due to the lack of reabsorption of the graft and the development of sclerosis in the osteotomy borders. CONCLUSIONS: The results of the present study show better osseointegration of the heterologous graft when nanohydroxyapatite is added.

ACL reconstruction with hamstrings: how different technique and fixation devices influence bone tunnel enlargement.

BACKGROUND: Bone tunnel enlargement after anterior cruciate ligament (ACL) reconstruction is well documented in the literature. The cause of this tunnel enlargement is unclear, but is thought to be multifactorial, with mechanical and biological factors playing a role. AIM: The aim of this prospective study was to evaluate how the different techniques may affect the bone tunnel enlargement and clinical outcome. PATIENTS AND METHODS: Forty-five consecutive patients undergoing ACL reconstruction with autologous doubled semitendinosus and gracilis tendons entered this study. They were randomly assigned to enter group A (In-Out technique, with cortical fixation and Interference screw) and group B (Out-In technique, metal cortical fixation on the femour and tibia). At a mean follow-up of 10 months, all the patients underwent CT scan exam to evaluate the post-operative diameters of both femoral and they underwent tibial tunnels clinical examination after 24 months. RESULTS: The mean femoral tunnel diameter increased significantly from 9.05±0.3 mm to 10.01±2.3 mm in group A and from 9.04±0.8 mm to 9.3±1.12 mm in group B. The mean increase in femoral tunnel diameters observed in group A was significantly higher than that observed in group B (p < 0.05) The mean tibial tunnel diameter increased significantly from 9.03±0.04 mm to 10.68±2.5 mm in group A and from 9.04±0.03 mm to 10.±0.78 mm in group B. The mean increase in tibial tunnel diameters observed in group A was significantly higher than that observed in group B (p < 0.05). No clinical differences were found between two groups and no correlations between clinical and radiological results were found in any patients of both groups. CONCLUSIONS: Results of the study suggest that different mechanical fixation devices could influence tunnel widening. The lower stiffness of the fixation devices is probably responsible of the tunnel widening through the fixation devices's micromotions in the femoral and tibial tunnels.

Nanohydroxyapatite-based bone graft substitute in tunnel enlargement after ACL surgery: RMN study.

BACKGROUND AND AIM: A successful anterior cruciate ligament reconstruction (ACL) requires solid healing of the tendon graft in the bone tunnel. New biological strategies have already been proposed with the aim of improving ACL graft healing and therefore allowing a faster rehabilitative program. The aim of this prospective study was to clinically and radiologically evaluate the efficacy of nanohydroxyapatite bone-base grafts in facilitating bone-tendon incorporation after ACL reconstruction with hamstrings (HS). As far as we know, this is the first study that has tried to asses the efficacy of such a type of bone substitute on human beings. MATERIALS AND METHODS: 40 male patients with chronic ACL rupture who underwent surgical reconstruction with 4-strand semitendinosus and gracilis tendon autograft via a single-bundle technique. Patients were randomly assigned to enter group A (20 patients, nanohydroxyapatite group) or group B (20 patients, control group). Preoperative and postoperative clinical evaluation was always performed, in a blinded way, assessing the Lachman and Pivot-shift tests and range of motion (ROM) of the affected knee. The Lysholm knee score, Tegner activity level, subjective and objective International Knee Documentation Committee (IKDC) forms, and 30 lb KT-1000 arthrometer evaluations. Patients underwent a magnetic resonance imaging (MRI) exam at 30, 90 and 180 days after surgery by the same musculoskeletal radiologist in a blinded way. RESULTS: As for the clinical evaluation, Lysholm, Tegner, IKDC scales, and KT-1000 arthrometer results did not show any significant difference between the two groups. Radiological data show a tendency toward better results in regard to the graft strength signal, the graftbone interface, and bone edema remodeling process, these parameters show significant differences between the two groups only at the short or mid-term follow-ups, while they are never significant at the mid-to long-term follow-up. CONCLUSIONS: In conclusion the use of nanohydroxyapatite bone substitute does not provide significant clinical improvements in terms of better knee stability or patient satisfaction.

Accuracy of manual instrumentation of tibial cutting guide in total knee arthroplasty.

PURPOSE: The aim of this study was to evaluate the accuracy of conventional instrumentation for tibial resection in total knee arthroplasty (TKA) as assessed by a computer-based navigation system during each phase of the surgical procedure. The hypothesis is that conventional instrumentation fails to achieve optimal accuracy in final implant positioning, thus leading to surgical errors. METHODS: Forty primary TKAs were performed. The resection guide was placed using an extramedullary guide. Accurate guide positioning was assessed by the navigation system prior to the osteotomy. The alignment measurement was repeated after resection and after component implantation in order to quantify the deviation caused by the manual positioning of the prosthetic components. A deviation ≥2° was considered unsatisfactory. RESULTS: In the frontal plane, unsatisfactory results observed were as follows: 15 % with reference to manual positioning of the resection guide and 10 % with reference to definition of the resection plane with a tendency towards varus malalignment. In the sagittal plane, unsatisfactory results were as follows: 45 % with reference to manual positioning of the resection guide and 40 % with reference to definition of the resection plane with a trend of decreased tibial slope angle. The deviation between bone resection and subsequent implant placement was ≥2° in none of the cases. CONCLUSIONS: The study confirms the hypothesis that conventional instrumentation fails to achieve optimal accuracy in the positioning of the tibial component. During each phase of the surgical procedure, a tendency towards varus malalignment and a decreased tibial slope angle were observed. LEVELS OF EVIDENCE: II.

Open-wedge high tibial osteotomy: comparison between manual and computer-assisted techniques.

PURPOSE: The purpose of our study was to compare clinical and radiological results of two groups of patients treated for medial compartment osteoarthritis of the knee with either conventional or computer-assisted open-wedge high tibial osteotomy (HTO). Goals of surgical treatment were a correction of the mechanical axis between 2° and 6° of valgus and a modification of posterior tibial slope between -2° and +2°. METHODS: Twenty-four patients (27 knees) affected by varus knee deformity and operated with HTO were prospectively followed-up. They were randomly divided in two groups, A (11 patients, conventional treatment) and B (13 patients, navigated treatment). The American Knee Society Score and the Modified Cincinnati Rating System Questionnaire were used for clinical assessment. All patients were radiologically evaluated with a comparative lower limb weight-bearing digital radiograph, a standard digital anteroposterior, a latero-lateral radiograph of the knee, and a Rosenberg view. RESULTS: Patients were followed-up at a mean of 39 months. Clinical evaluation showed no statistical difference (n.s.) between the two groups. Radiological results showed an 86% reproducibility in achieving a mechanical axis of 182°-186° in group B compared to a 23% in group A (p = 0.0392); furthermore, in group B, we achieved a modification of posterior tibial slope between -2° and +2° in 100% of patients, while in group A, this goal was achieved only in 24% of cases (p = 0.0021). CONCLUSION: High tibial osteotomy with navigator is more accurate and reproducible in the correction of the deformity compared to standard technique. LEVEL OF EVIDENCE: Therapeutic study, Level II.

Computer-assisted surgery: a teacher of TKAs.

INTRODUCTION: The hypothesis of this study is that computer-aided navigation experience could improve the ability to better place components in the coronal plane and to improve visual/spatial awareness based on the ability of navigation to provide instant feedback. The purpose of this study is to demonstrate the educational role of the navigation system to obtain a better alignment of the prosthetic components with standard instrumentation after a computer-aided navigation experience. MATERIALS AND METHODS: One hundred fifty patients were operated by the same surgeon, with more than 5 years experience with TKA. They were equally divided in three groups: group A (operated with non-navigated technique by surgeon without computer-assisted experience); group B (operated with computer-assisted surgery by the same surgeon); group C (operated with non-navigated technique by the same surgeon after the computer-navigated experience). We evaluated by full-length weight-bearing radiographs the overall alignment of the lower limb in the coronal plane. The optimum placement of the components was considered when the angle was within the limits of ±3° varus/valgus on the coronal x-rays. Comparison between groups was done using one-way ANOVA followed by post hoc Bonferroni test and Pearson chi-square statistics for proportions of optimum placement (P<0.05). RESULTS: In the group A 34 patients (68%) had the optimum placement on the coronal x-rays; in the group B they were 46 (92%) and in the group 41 (82%). The difference is statistically significant in comparing group A and Group B (<0.001), group A and group C (P=0.04), but not for group B and C (P=0.2). CONCLUSION: We believe that the navigation system has an educational role to improve the ability of surgeon of positioning prosthetic components precisely in the coronal plane.

Tibial stress fracture after computer-navigated total knee arthroplasty.

A correct alignment of the tibial and femoral component is one of the most important factors determining favourable long-term results of a total knee arthroplasty (TKA). The accuracy provided by the use of the computer navigation systems has been widely described in the literature so that their use has become increasingly popular in recent years; however, unpredictable complications, such as displaced or stress femoral or tibial fractures, have been reported to occur a few weeks after the operation. We present a case of a stress tibial fracture that occurred after a TKA performed with the use of a computer navigation system. The stress fracture, which eventually healed without further complications, occurred at one of the pinhole sites used for the placement of the tibial trackers.

Achilles tendon surgical revision with synthetic augmentation.

In this paper we report about a 50-year-old patient who underwent a surgical revision procedure for rupture of the right Achilles tendon with the use of Ligastic((R)) synthetic graft in 1995, and in which a strong reactive immune response took place over the graft 11 years after. As far as we know, this is the first case described in literature of long-term follow-up inflammatory reaction after the use of such augmentation grafts in Achilles tendon repair.

Blood loss in computer-assisted mobile bearing total knee arthroplasty. A comparison of computer-assisted surgery with a conventional technique.

Computer-assisted surgery (CAS) in total knee arthroplasty (TKA) could be useful in reducing the overall blood loss. A prospective randomised study was performed with two groups of 50 patients each of whom were treated for knee arthritis. Patients of group A were treated by a conventional standard procedure, while for patients of group B a specific CAS procedure was used. We determined the intraoperative blood loss according to the Orthopaedic Surgery Transfusion Haemoglobin European Overview (OSTHEO) study. The average blood loss in patients of group A was 1,974 ml (range: 450-3,930 ml) compared to 1,677 ml of patients of group B (range: 500-2,634 ml). A statistically significant difference was found between the two groups (p = 0.0283). Computer-assisted surgery is highly recommended in TKR to save blood. It creates more possibilities to operate on anaemic patients and subjects who cannot accept blood products by reducing blood loss risk.

Tunnel enlargement after anterior cruciate ligament reconstruction in patients with post-operative septic arthritis.

Tunnel enlargement is a frequent issue after ACL reconstruction and the "synovial bathing effect" is thought to be among the biological factors contributing to this phenomenon. Since the amount and the pressure of the synovial fluid inside the knee joint are higher and the length of its presence is longer in patients with post-operative septic arthritis after ACL reconstruction, we reviewed the tunnel enlargement in these cases in order to better evaluate this phenomenon in such a hostile environment. The null hypothesis of this study was that the highly represented phenomenon of the "synovial bathing effect" that occurs in an infected ACL reconstruction would not affect the amount of post-operative tunnel widening. A case-control study was done. At a mean follow up of 10 months (range 9-11 months) eight patients with septic arthritis following ACL reconstruction (group A) were radiologically reviewed using a CT scan and the diameters of femoral and tibial tunnels were measured. The results were compared with a control group (B) of uncomplicated ACL reconstruction cases operated by the same surgeon using the same technique. Although patients of Group A experienced a bigger amount of tunnel enlargement than patients of group B both on femoral (9.53 +/- 1.07 vs. 9.35 +/- 1.52 mm) and tibial side (10.07 +/- 1.3 vs. 9.92 +/- 0.74 mm), no clinical or statistically significant differences were detected between the groups (P > 0.05). No significant tunnel enlargement could be detected in patients of group A when compared with patients of group B. This seems to minimize the role of biological factors contributing to tunnel widening.

Double bundle or single bundle plus extraarticular tenodesis in ACL reconstruction? A CAOS study.

Anatomic reconstructions of anterior cruciate ligament (ACL) with double bundle gracilis and semitendonosus tendons graft, reproducing AM and PL bundles, have been introduced to offer a better biomechanical outcome, especially during rotatory loads. On the other hand, many methods of tenodesing the lateral aspect of the tibia to the femur to reduce internal rotation (IR) of the tibia and minimize anterior translation of the tibia relative to the femur as a backup for intra-articular reconstruction, have been also suggested. The goal of this study is to evaluate the effect, on the IR of the tibia, of a lateral reconstruction in addition to a standard single bundle ACL reconstruction as compared with an anatomic double bundle ACL reconstruction. Computer assisted ACL reconstruction has been used because it could be very effective in evaluating the global kinematic performance of the reconstructed knee. We selected 20 consecutive ACL reconstruction procedures to be performed in males in our hospital. Patients were alternately assigned to one of the two groups--group A: standard single bundle ACL reconstruction with doubled gracilis and semitendinosus tendons graft with an arthroscopically assisted two incisions technique and a lateral extraarticular reconstruction; group B: double bundle ACL reconstruction with doubled gracilis and semitendinosus tendons graft with an arthroscopically assisted two incisions technique. In all ACL reconstruction procedures navigation process was performed. Both surgical techniques reduced significantly AP displacement, IR and external rotation (ER) of the tibia respect to pre-operative ACL deficient condition (p<0.05). Comparing the group A after the single bundle reconstruction and the group B after the AM bundle fixation, non differences were found in AP displacement, IR and ER of the tibia (p=0.75, p=0.07 and p=0.07 respectively; power: 0.94). Comparing the group A after the addition of the lateral tenodesis and group B after the PL bundle fixation (AM+PL) no differences in AP tibial displacement and in ER of tibia were found (p=0.9 and 0.15, respectively; power: 0.99); however a significant reduction in IR of the tibia was found in group A after the addition of the lateral tenodesis respect to the group B after the addition of the PL bundle (p=0.0001; power: 0.26). On the basis of our study, the addition of a lateral extraarticular reconstruction to a standard single bundle ACL reconstruction with hamstrings tendons graft in an "in vivo" reconstruction, is more effective in reducing the IR of the tibia at 30 degrees of knee flexion, as compared with a standard single bundle ACL reconstruction and with an anatomic double bundle reconstruction is confirmed.

Reconstruction of the anterior cruciate ligament with the tendons of the semitendinosus and gracilis doubled: a comparison with reconstruction using the patellar tendon.

A total of sixty consecutive cases of anterior chronic laxity of the knee the pre- and intraoperative features of which corresponded to the criteria of inclusion considered, hospitalized in our institute between September and December 1998 and submitted to reconstruction of the ACL were reviewed at a follow-up of 74 months. The series was made up of two groups that were homogeneous in terms of sex, age, degree of preoperative laxity and number and type of associated meniscal lesions; in the first group (20 cases) reconstruction was carried out using the patellar tendon (BPTB) and in the other (40 cases) the doubled semitendinosus and gracilis tendons (DGST) were used with the association in cases with greater rotatory laxity (20 cases) of peripheral reinforcement reconstruction. An accelerated rehabilitation protocol was used in the first group, a more prudent one with immobilization in extension for two weeks was used in the second group. The results, evaluated based on the IKDC form, appeared to be better in the DGST group, with a statistically significant difference; joint stability, evaluated at follow-up with a KT1000 arthrometer also proved to be better in the DGST group, with a difference that was not statistically significant. The present study seems to show that reconstruction of the ACL with DGST, a prudent rehabilitation protocol and peripheral reinforcement reconstruction in selected cases is capable of providing better long-term results as compared to standard reconstruction with the patellar tendon and accelerated rehabilitation protocol. Among methods used to reconstruct the anterior cruciate ligament (ACL), those that utilize the central third of the patellar tendon (BPTB) or the semitendinosus and gracilis tendons (DGST) continue to be those used most frequently. Although the debate between orthopedics is still going on as to which of the two methods is to be preferred, studies that compare the two methods do not seem to report essential differences in medium-term results. In a recent meta-analysis of the most important international literature, to this regard Freedman et al. concluded that despite a significant major presence of anterior pain reconstruction with BPTB is capable of guaranteeing better joint stability and patient satisfaction, with a minor incidence of transplant failure. Nonetheless, if methods of reconstruction with BPTB seem to be rather standardized in terms of the method used to obtain the specimen and that used for stabilization (with very few differences between interference screws and transverse stabilization), and in postoperative rehabilitation (so-called accelerated), when DGST is used there are many technical variables capable of influencing the final results (choice of methods of stabilization, postoperative rehabilitation in particular). For this reason we still cannot obtain an absolute comparison of the two methods, but can only compare reconstruction with BPTB and a particular method used with DGST. It is the purpose of this study to present the medium-term results not so much of ACL reconstruction with the semitendinosus and gracilis doubled, but as a more articulate approach to the pathology of the ACL, so that DGST is only one phase, even if it is the most important one. Because we wished to verify whether it is possible, even in terms of joint stability and patient satisfaction, to improve the results of the so-called gold standard for reconstruction of the ACL, reconstruction by BPTB with transverse femoral reconstruction and accelerated postoperative rehabilitation protocol was chosen as a term of paragon.

Viscoelastic properties of the semitendinosus and gracilis tendons in reconstruction of the ACL: an in vivo evaluation.

Tensioning of the tendons of the semitendinosus and the gracilis used to reconstruct the anterior cruciate ligament (ACL) of the knee is one of the main factors to take into consideration during surgery that aims at obtaining good postoperative joint stability. Some authors have shown in vitro that the viscoelastic nature of the patellar tendon is responsible for its gradual release (loss of tension). It is the purpose of this study to verify in vivo the biomechanical behavior of the semitendinosus and gracilis tendons. A total of 40 consecutive patients were submitted to reconstruction of the ACL with flexor tendons of the knee using a method that allows for the gradual tensioning of the doubled semitendinosus and gracilis tendons using the Swing Bridge method. Patients were divided into 2 groups: in the first 20 patients (group I), after adequate manual pretensioning and tibial and femoral stabilization, the tendons were twisted using a dynamometer to measure torsion forces until tensioning equal to 2.5 N was achieved. The control group (group II) was made up of the successive 20 patients in whom tensioning of the tendons at 2.5 N was carried out in many phases. Five minutes after initial tensioning at 2.5 N the decrease in tension was recorded that returned to initial values. A similar procedure was carried out after 5 more minutes. The patients in both groups were evaluated using a KT-1000 arthrometer one year after surgery. The patients in group II showed a decrease in torsion equal to 37.2% after the first 5 minutes, and a further 26.8% after 5 more minutes, and measurement by means of KT-1000 revealed mean values for S/S 30 lb. and S/S MM of 1.3 mm and 1.7 mm, respectively, that proved to have a statistically significant difference (p < 0.05) as compared to the patients in group I (S/S 30 lb.: 2.0 mm; S/S MM: 2.4 mm). Although these data do not provide indications on the amount and duration of pretensioning and definitive tensioning to be applied to the transplant, they do clearly show the viscoelastic properties of the tendons. These properties require a more in-depth study to better determine the exact tensioning of the neoligament.

Biomechanics of anterior cruciate ligament reconstruction using twisted doubled hamstring tendons.

We studied the biomechanical properties of a twisted doubled semitendinosus and gracilis graft. We applied an un-axial load in order to reproduce the kinematics of a reconstructed anterior cruciate ligament (ACL). A modified cryo-jaw clamp system was used to minimize soft tissue slippage. The lower grip, after fixation of the free ends of the tendons, was rotated 45 degrees, translated 1 cm, and bent 40 degrees, simulating a knee sprain. The graft was tested to failure using a servohydraulic machine. The specimen from one knee of seven unembalmed cadavers was assigned to the untwisted (parallel) bundles group, while its pair was assigned to the twisted group. For the parallel bundles group, the mean maximum load was 1,709.3+/-581.9 N, for the twisted group 2,428.3+/-475.4 N (P<0.05). The mean stiffness was respectively 213.6+/-72.4 N/mm and 310.3+/-97.3 N/mm (P=0.08). Although caution should be used in extrapolating the results to clinical estimates of the strength of hamstring grafts, the results of the present study could justify the use of twisted semitendinosus and gracilis bundles in ACL reconstruction.

Regeneration of the semitendinosus tendon harvested for anterior cruciate ligament reconstruction. Evaluation using ultrasonography.

In a prospective study, 40 consecutive patients who underwent anterior cruciate ligament reconstruction with doubled semitendinosus and gracilis tendon autografts were examined pre- and postoperatively by ultrasound to investigate the anatomy of the donor site before and after the harvest of the tendons. The patients underwent ultrasonography at 2 weeks and 1, 2, 3, 6, 12, 18, and 24 months postoperatively. A total of 298 postoperative sonographic evaluations were performed. The semitendinosus tendon was imaged in the sagittal and axial planes: structure and margins were evaluated with the sagittal views; thickness and width were measured with the axial views. In all cases the following sequence of healing was documented: 2 weeks after surgery the semitendinosus tendon site was occupied by an area of increased thickness and decreased echogenicity, suggesting the presence of traumatic edema of the soft tissue surrounding the tenotomy. At 1 month, an irregular hypoechoic structure appeared in a near-anatomic position; at 2 months after surgery, thickness, width, and cross-sectional area of this structure were significantly greater than preoperatively. The amount of regenerated tissue increased up to that seen in the tissue of the 6-month examinations, which also showed a more uniform echostructure. The scans performed at 1 year showed distinct edges and reduction in thickness and width. At 18 and 24 months the echogenicity of the structure occupying the donor site was very similar to that of the normal semitendinosus tendon. However, this structure was clearly identified about 4 cm proximal to the pes anserinus, revealing a more proximal insertion of the regenerated semitendinosus tendon.

Open capsulorrhaphy with suture anchors for recurrent anterior dislocation of the shoulder.

Forty of 42 consecutive open capsulorrhaphies with suture anchors for treatment of traumatic recurrent anterior dislocation of the shoulder were reviewed after a minimum follow-up of 2 years. Two patients were lost to follow-up. Follow-up was conducted according to the rating systems of Rowe and the Society of American Shoulder and Elbow Surgeons. The surgical outcome was satisfactory in 38 patients (95%). Eighteen of the 22 patients who were involved in competitive overhead or collision sports before surgery returned to their preoperative sports levels. One patient, whose operation was unsuccessful, experienced recurrent dislocation. In one patient a deep infection that occurred as a complication of the surgical technique healed after suture anchor removal. Although a longer follow-up is necessary, this technique appears to have encouraging results as it avoids the risks related to the use of screws and staples.

Knee ligament injuries in volleyball players.

The authors report a series of 52 cases of serious knee ligament injuries in volleyball players. The most frequent mechanism of injury was landing from a jump in the attack zone. Women were more affected than men. Injuries were more frequent during games than training. Volleyball must then be considered among high-risk sports according to the frequency and gravity of our surgical findings. Results are similar to those obtained in athletes in other sports who underwent the same surgical procedure.

Arthroscopic treatment of flexion deformity after ACL reconstruction.

After anterior cruciate ligament (ACL) reconstruction, one frequent complication is the restriction of the range of motion and loss of extension. In addition to the presence of adhesions in the suprapatellar pouch, it is possible to detect two different pathological findings in the intercondylar notch: a misplacement of graft causing an intercondylar impingement, or the presence of hypertrophic tissue originating from the graft that blocks the last degrees of extension, causing an "anterior impingement." We reviewed 18 consecutive cases treated by arthroscopic release. All patients had knee range-of-motion restriction after an ACL procedure. The follow-up at 1 and at 6 months shows that good results have been obtained in cases of anterior impingement, whereas in cases of intercondylar impingement a restricted range of motion, especially of flexion, did remain. In all cases, after arthroscopic treatment the postoperative extension was between 5 and 10 degrees, but this deficit regressed after 6 months in 12 patients, whereas a dropout case was necessary in the remaining 6 patients.

Chondromalacia and chronic anterior instabilities of the knee.

In this study, we surveyed a consecutive series of 500 patients who had undergone an open procedure for chronic anteromedial and/or anterolateral instabilities. Those patients who had an open arthrotomy were separated for analysis. All of the patients were examined before and during surgery. A knee sheet, based on the kind used at the Hughston Orthopaedic Clinic in Columbus, Georgia, was used to record all clinical findings. Chondromalacia of the articular surface of the femur was detected at surgery in 161 patients (32%). A statistical analysis showed that the variables directly influencing degenerative changes of the cartilage are: a previous surgery that did not sufficiently restore joint kinematics (chi square = 20.238, P less than 0.001) and a time lapse of more than 30 months between first trauma and surgery (chi square = 21.736; P = 0.001). A higher score on dynamic (jerk or pivot shift) and static (internal and external anterior drawer) tests, indicating instability, or a meniscal tear alone do not statistically correlate with chondromalacia, but together they influence degenerative changes of the cartilage.

Osteoarthritis of the knee after ACL reconstruction.

One hundred and fourteen knees with deficiency of the anterior cruciate ligament (ACL) which had undergone reconstruction of the ligament using semitendinosus and gracilis were reviewed at a mean of 61 months after operation. Radiological and clinical evaluation was undertaken. A significant correlation was found between the number of meniscectomies performed in acute cases and those undertaken on the chronic knee. There was also significant correlation between meniscectomy and the Fairbank grading of degenerative changes seen on the radiographs. There was no correlation between the clinical results, residual laxity and the development of osteoarthritis. In ACL deficient knees with irreparable meniscal tears, or in which meniscectomy had been undertaken, the development of osteoarthritis seemed independent of the degree of stability, but in such knees with no meniscal tear or meniscal repair, reconstruction appeared to save the menisci and preserve the joint.