Anterior cruciate ligament reconstruction with 4-strand hamstring autograft and accelerated rehabilitation: a 10-year prospective study on clinical results, knee osteoarthritis and its predictors

Purpose

Analysis of long-term clinical and radiological outcomes after anterior cruciate ligament (ACL) reconstruction with special attention to knee osteoarthritis and its predictors.

Methods

A prospective, consecutive case series of 100 patients. Arthroscopic transtibial ACL reconstruction was performed using 4-strand hamstring tendon autografts with a standardized accelerated rehabilitation protocol. Analysis was performed preoperatively and 10 years postoperatively. Clinical examination included Lysholm and Tegner scores, IKDC, KT-1000 testing (MEDmetric Co., San Diego, CA, USA) and leg circumference measurements. Radiological evaluation included AP weight bearing, lateral knee, Rosenberg and sky view X-rays. Radiological classifications were according to Ahlbäck and Kellgren & Lawrence. Statistical analysis included univariate and multivariate logistic regressions.

Results

Clinical outcome A significant improvement (p < 0.001) between preoperative and postoperative measurements could be demonstrated for the Lysholm and Tegner scores, IKDC patient subjective assessment, KT-1000 measurements, pivot shift test, IKDC score and one-leg hop test. A pivot shift phenomenon (glide) was still present in 43 (50 %) patients and correlated with lower levels of activity (p < 0.022). Radiological outcome: At follow-up, 46 (53.5 %) patients had signs of osteoarthritis (OA). In this group, 33 patients (72 %) had chondral lesions (≥grade 2) at the time of ACL reconstruction. A history of medial meniscectomy before or at the time of ACL reconstruction increased the risk of knee OA 4 times (95 % CI 1.41–11.5). An ICRS grade 3 at the time of ACL reconstruction increased the risk of knee OA by 5.2 times (95 % CI 1.09–24.8). There was no correlation between OA and activity level (Tegner score ≥6) nor between OA and a positive pivot shift test.

Conclusion

Transtibial ACL reconstruction with 4-strand hamstring autograft and accelerated rehabilitation restored anteroposterior knee stability. Clinical parameters and patient satisfaction improved significantly. At 10-year follow-up, radiological signs of OA were present in 53.5 % of the subjects. Risk factors for OA were meniscectomy prior to or at the time of ACL reconstruction and chondral lesions at the time of ACL reconstruction.

Level of evidence

II.     

Double-bundle reconstruction results in superior clinical outcome than single-bundle reconstruction

Purpose

To compare the short- and long-term clinical outcomes of the double-bundle (DB) anterior cruciate ligament (ACL) reconstruction with those of single-bundle (SB) ACL reconstruction.

Methods

An electronic search of the database PubMed (1966–September 2011), EMBASE (1984–September 2011), and Cochrane Controlled Trials Register (CENTRAL; 3rd Quarter, 2011) was undertaken to identify relevant studies. Main clinical outcomes were knee stability measurements including KT-1000 arthrometer measurement, Pivot shift test, and Lachman test, and clinical outcome measurements including International Knee Documentation Committee (IKDC), Lysholm knee score, Tegner activity score, and complications.

Results

Eighteen studies were finally included in this meta-analysis, which were all classified as high risk of bias according to the Collaboration’s recommended tool. It is seen that compared to SB ACL reconstruction, DB ACL reconstruction results in a KT-1000 arthrometer outcome 0.63 and 1.00 mm closer to the normal knee in a short- and long-term follow-up, respectively. Our results also reveal that DB-treated patients have a significantly higher negative rate of the pivot shift test (p < 0.00001 and = 0.006 in a short- and long-term follow-up, respectively) and Lachman test (n.s. and p < 0.0001 in a short- and long-term follow-up, respectively) compared to SB-treated patients. As for the clinical outcome measurements, a significant difference is found between SB versus DB ACL reconstruction regarding the IKDC (p = 0.006 and < 0.0001 in a short- and long-term follow-up, respectively) and complications (p = 0.03), while there is no significant difference between the two groups regarding Lysholm knee score (n.s.) and Tegner activity score (n.s.).

Conclusion

Overall, double-bundle ACL reconstruction yields better clinical outcomes when compared to single-bundle ACL reconstruction.

Levels of evidence

II.     

Combined ACL reconstruction and closing-wedge HTO for varus angulated ACL-deficient knees

Purpose

To report the medium-term clinical and radiographic outcomes of a group of patients who underwent anterior cruciate ligament (ACL) surgery combined with high tibial osteotomy (HTO) for varus-related early medial osteoarthritis (OA) and ACL deficiency knee.

Methods

Thirty-two patients underwent single-bundle over-the-top ACL reconstruction or revision surgery and a concomitant closing-wedge lateral HTO. The mean age at surgery was 40.1 ± 8.1 years. Evaluation at a mean of 6.5 ± 2.7 years of follow-up consisted of subjective and objective IKDC, Tegner Activity Level, EQ-5D, VAS for pain and AP laxity assessment with KT-1000 arthrometer. Limb alignment and OA changes were evaluated on radiographs.

Results

All scores significantly improved from pre-operative status to final follow-up. KT-1000 evaluation showed a mean side-to-side difference of 2.2 ± 1.0 mm. Two patients were considered as failures. The mean correction of the limb alignment was 5.6° ± 2.8°. Posterior tibial slope decreased at a mean of 1.2° ± 0.9°. At final follow-up, the mechanical axes crossed the medial–lateral length of tibial plateau at a mean of 56 ± 23 %, with only 1 patient (3 %) presenting severe varus alignment. OA progression was recorded only on the medial compartment (p = 0.0230), with severe medial OA in 22 % of the patients. No patients underwent osteotomy revision, ACL revision, UKA or TKA.

Conclusions

The described technique allowed patients with medial OA, varus alignment and chronic ACL deficiency to restore knee laxity, correct alignment and resume a recreational level of activity at 6.5 years of follow-up.

Level of evidence

Case series with no comparison group, Level IV.     

Nonoperative treatment for anterior cruciate ligament injury in recreational alpine skiers

Purpose

The purpose of this study was to test whether low-grade Lachman test (i.e. Grade 0–1+) and a negative pivot shift at 6–12 weeks post-ACL rupture in recreational alpine skiers can be used to predict good function and normal knee laxity in nonoperated patients at minimum 2 years after the injury.

Methods

Office registry was used to identify 63 recreational alpine skiers treated by the senior author within 6 weeks of a first-time ACL injury between 2003 and 2008. Of these, 34 had early ACL reconstruction but 29 patients were observed and re-evaluated. Office charts and MRI were reviewed. Inclusion criteria for this study were as follows: ACL rupture documented on MRI after the injury, and minimum 2-year follow-up. Exclusion criterion was contralateral knee ligament injury. Of the 29 patients treated nonoperatively, 17 had low-grade Lachman and negative pivot shift tests within 6–12 weeks after the injury and were recommended to continue follow-up without surgery. Of these 17 patients, 6 were lost to follow up, but 11 patients were recalled and evaluated at more than 2 years after the injury. They completed Marx and Tegner activity level and IKDC subjective scores, physical examination of the knee and KT-1000 anterior laxity assessment.

Results

Median age at injury was 43 years (range 29–58). Median follow-up was 42 months (range 30–68). Mean IKDC subjective score at latest follow-up was 91.6 ± 6.7. Median Tegner score was 6 (range 6–9) before the injury and 6 (range 4–6) at latest follow-up (p = n.s). Median Marx score was 6 (range 0–16) before the injury and 4 (range 0–12) at latest follow-up (p = 0.03). Ten patients had Lachman Grade 0–1+, and one had Lachman Grade 2+ at latest follow-up. KT-1000 showed mean side-to-side difference of 0.8 ± 1.6 mm, and less than 3 mm difference in the 10 patients with Lachman Grade 0–1+.

Conclusion

Recreational alpine skiers who sustain ACL injury should be re-evaluated at 6–12 weeks after the injury rather than being operated acutely. If they have negative Lachman and pivot shift tests at that point, they can be treated without surgery since good outcome and normal knee anterior laxity at more than 2 years after the injury is expected.

Level of evidence

Case series, Level IV.     

Is osteoarthritis an inevitable consequence of anterior cruciate ligament reconstruction? A meta-analysis

Purpose

Although the occurrence of early osteoarthritis (OA) is commonly associated with a history of anterior cruciate ligament (ACL) reconstruction, its exact prevalence in these patients remains unknown. The goal of this study was to review the current literature on long-term radiographic outcome after autologous ACL reconstruction and subsequently perform a meta-analysis to obtain evidence-based prevalences of OA at a mean of 10 years after surgery. In addition, this report aimed at identifying the relationship between meniscal status and the occurrence of radiographic OA in the ACL reconstructed knee.

Methods

A systematic review of the literature was performed in PubMed MEDLINE, EMBASE and Cochrane Library databases to identify all studies concerning radiographic outcome after autologous ACL reconstruction with a follow-up of minimum 10 years. Meta-analyses were performed to obtain the average prevalence of OA and the difference between patients with and without meniscectomy. Considered study estimates were the log-transformed odds and odds ratios, the latter expressing the effect of meniscectomy on OA.

Results

A total of 16 studies could be included for meta-analysis, accounting for 1554 ACL reconstructions performed between 1978 and 1997. Of these knees, 453 (28 %) showed radiological signs of osteoarthritis (IKDC grade C or D). Furthermore, 50 % of the patients with meniscectomy had osteoarthritis, compared with 16 % of the patients without meniscectomy. The combined odds ratio for meniscectomy equals 3.54 (95 % CI 2.56–4.91).

Conclusions

The main finding of this meta-analysis is that the prevalence of radiographic knee OA after ACL reconstruction is lower than commonly perceived. However, associated meniscal resection dramatically increases the risk for developing OA.

Level of evidence

Level III.     

The prevalence of patellofemoral osteoarthritis 12 years after anterior cruciate ligament reconstruction

Purpose

To investigate the prevalence of patellofemoral osteoarthritis (OA) and to explore the association between radiographic patellofemoral OA and symptoms and function 12 years after anterior cruciate ligament (ACL) reconstruction.

Methods

The study participants (n = 221) were consecutively included at the time of an ACL reconstruction in the period from 1990 to 1997. Knee laxity (KT-1000), isokinetic quadriceps strength, triple jump, stair hop, and the Cincinnati knee score were measured 6 months, 1 year, 2 years, and 12 years after surgery. At the 12-year follow-up, visual analogue scale for pain, the Knee injury and Osteoarthritis Outcome Score, the Tegner activity scale, and radiographic examination (Kellgren and Lawrence score) were added. To analyse the association between patellofemoral OA, symptoms, and function, binary regression analyses presenting odds ratios and 95 % confidence intervals were used. The analyses were adjusted for age, gender, and body mass index.

Results

One hundred and eighty-one of the 221 subjects (82 %), including 76 females (42 %) and 105 males (58 %), were evaluated at the 12.3 ± 1.2-year follow-up. Mean age at the follow-up was 39.1 ± 8.7 years. Additional meniscal or chondral injuries at the time of reconstruction or during the follow-up period were detected in 116 subjects (64 %). Radiographic patellofemoral OA was found in 48 subjects (26 %), including 3 subjects with isolated patellofemoral OA (1.5 %). Those with patellofemoral OA were older, had more tibiofemoral OA, and had significantly more symptoms and impaired function compared with those without patellofemoral OA.

Conclusions

Patellofemoral OA was found in 26 % 12 years after ACL reconstruction. Patellofemoral OA was associated with increased age, tibiofemoral OA, increased symptoms, and reduced function. It is of clinical importance to include functional and radiographic assessment of the patellofemoral joint in the examination of long-term consequences following an ACL reconstruction.

Level of evidence

II.     

Comparison of T1rho relaxation times between ACL-reconstructed knees and contralateral uninjured knees

Purpose

The goal of this study is to compare the cartilage of anterior cruciate ligament (ACL)-reconstructed and uninjured contralateral knees using T _1ρ MRI 12–16 months after ACL reconstructions.

Methods

Eighteen patients with ACL-reconstructed knees (10 women, 8 men, mean age = 38.3 ± 7.8 years) were studied using 3T MRI. Injured and contralateral knee MR studies were acquired 12–16 months post-operatively. Cartilage sub-compartment T _1ρ values of each injured knee were compared with the contralateral knee’s values. Subgroup analysis of sub-compartment T _1ρ values in both knees was performed between patients with and without meniscal tears at the time of ACL reconstruction using a paired Student’s t test.

Results

In ACL-injured knees, the T _1ρ values of the medial tibia (MT) and medial femoral condyle (MFC) were significantly elevated at 12–16 months follow-up compared to contralateral knees. Patients with a medial meniscal tear had higher MFC and MT T _1ρ values compared to respective regions in contralateral knees. Patients with lateral meniscal tears had higher lateral femoral condyle and LT T _1ρ values compared to respective regions in contralateral knees. There were no differences between the injured and contralateral knees of patients without meniscal tears.

Conclusions

T _1ρ MRI can detect significant changes in the medial compartments’ cartilage matrix of ACL-reconstructed knees at 1 year post-operatively compared to contralateral knees. The presence of a meniscal tear at the time of ACL reconstruction is a risk factor for cartilage matrix degeneration in the femorotibial compartments on the same side as the meniscal tear.     

Comparison of Achilles and tibialis anterior tendon allografts after anterior cruciate ligament reconstruction

Purpose

The purpose of this study was to compare the outcomes after anterior cruciate ligament (ACL) reconstruction using Achilles tendon allografts and tibialis anterior (TA) tendon allografts with respect to objective knee testing measures, second-look arthroscopy and femoral tunnel enlargement.

Methods

A total of 131 patients who underwent ACL reconstruction between 2000 and 2006 were retrospectively reviewed. Achilles tendon allografts were used in 81 patients (group I). These patients were compared with 50 patients in whom TA tendon allografts were used (group II). The two groups were assessed using International Knee Documentation Committee (IKDC), Lysholm and Tegner activity scores, as well as KT-2000 testing. Second-look arthroscopic findings were evaluated. Cross-sectional area (CSA) perpendicular to the long axis of the femoral tunnel was also calculated digitally using magnetic resonance imaging.

Results

No significant differences were observed between the two groups with respect to IKDC, Lysholm or Tegner activity scores or the results of laxity testing with arthrometry. Synovial coverage of more than 50 % was found in 71.1 % cases in group I and 75 % cases in group II. Mean CSA enlargement of 15 % (group I) and 38 % (group II) was detected (p = 0.017).

Conclusions

The clinical results associated with Achilles and TA tendons were not significantly different. The laxity evaluation and second-look arthroscopy demonstrated no significant differences between group I and group II. However, Achilles tendon-bone plugs for femoral tunnel fixation reduced femoral tunnel enlargement compared to the TA allograft. Achilles tendon allografts for ACL reconstruction could be a reasonable option in selected patients.

Level of evidence

Retrospective case series, Level IV.     

An isolated rupture of the posterior cruciate ligament results in reduced preoperative knee function in comparison with an anterior cruciate ligament injury

Purpose

To investigate differences in preoperative knee function (Knee Injury and Osteoarthritis Outcome Score, KOOS), the time period from injury to surgery, and associated injuries when comparing primary isolated posterior cruciate ligament (PCL) and primary anterior cruciate ligament (ACL) reconstructions.

Methods

Isolated primary ACL and PCL reconstructions registered in the Norwegian National Knee Ligament Registry from 2004 through 2010 were included (n = 71 primary PCLs and 9,649 primary ACLs). Linear regression analysis was used to evaluate the preoperative KOOS subscale values.

Results

The preoperative KOOS in the PCL group (n = 71) and ACL group (n = 9,649) was significantly different for the subscales symptoms (mean difference, ?8.4; 95 % CI: ?12.8 to ?4.0), pain (mean difference, ?15.9; 95 % CI: ?20.3 to ?11.4), activities of daily living (mean difference, ?12.9; 95 % CI: ?17.4 to ?8.4), sport and recreation (mean difference, ?15.9; 95 % CI: ?22.6 to ?9.3), and quality of life (mean difference, ?7.9; 95 % CI: ?12.4 to ?3.5). The primary isolated PCL-reconstructed knees had a median time from injury to surgery of 21 months in comparison with 8 months for ACL injuries. The ACL-injured knees had more associated injuries (meniscus and full-thickness cartilage lesions) than the PCL-injured knees.

Conclusion

Surgically treated knees with an isolated rupture of the PCL exhibited worse knee function preoperatively compared with knees with an isolated ACL injury; in addition, the delay to surgery was longer. Meniscal lesions were found more frequently in ACL-injured knees.

Level of evidence

Prospective cohort study, evidence Level I.     

Gender differences following computer-navigated single- and double-bundle anterior cruciate ligament reconstruction

Purpose

Female patients not only demonstrate an increased risk for injury, but also a poorer response following anterior cruciate ligament (ACL) rupture. However, no study has investigated gender-related differences between computer-navigated single-bundle (SB) and double-bundle (DB) ACL reconstruction. The aim of this study was to evaluate the effects of gender on the outcome of computer-navigated SB and DB ACL reconstruction and to present reference values.

Methods

A retrospective review of 55 consecutive patients who underwent SB (15 males, 12 females) and DB (18 males, 10 females) ACL reconstruction with autogenous hamstring tendon grafts and showed a minimum follow-up of 24 months was conducted. Intraoperatively, the anteroposterior and rotational laxity were measured and the follow-up examination included pivot-shift testing, KT-1000 arthrometer testing, International Knee Documentation Committee (IKDC) form, the Lysholm score and Tegner score.

Results

Pre-operatively, female patients showed a significant higher internal rotation in (p < 0.001) both the SB and DB group. Regarding the post-operative reduction in internal rotation, females in the SB group revealed a greater reduction compared to males (p < 0.001), whereas females in the DB group revealed a significantly greater post-operative reduction in anterior–posterior translation (p = 0.04). Female patients following DB ACL reconstruction presented a significant worse IKDC score, Lysholm score and Tegner score compared to male patients. All score values of the female DB group were worse than in the female SB group. In contrast, male patients showed better results of all examined clinical scores following DB procedure compared to SB technique.

Conclusion

Female patients who underwent computer-navigated DB ACL reconstruction exhibited significantly worse outcome scores than males who underwent DB ACL reconstruction. The gender-based relationship between joint function and outcome after ACL reconstruction remains unclear and requires further investigation.

Level of evidence

Retrospective case–control series, Level III.     

The influence of femoral tunnel position in single-bundle ACL reconstruction on functional outcomes and return to sports

Purpose

The purpose of this study was to radiographically investigate the influence of femoral tunnel placement in ACL reconstruction on early outcomes and return to sports due to anatomic and nonanatomic positioning.

Methods

A prospective study was conducted from 2008 to 2010, with 86 athletes who underwent ACL reconstruction between anteromedial (AM) footprint and high AM position. Knee functional outcomes (IKDC objective and subjective, Tegner score, and Lysholm scale) return to sports and complications were analyzed at 6- and 12-month follow-up.

Results

At follow-up, it was observed that tunnel projection along Blumensaat’s line was correlated with functional outcomes on Tegner scale (at 6 and 12 months) and IKDC subjective (at 12 months). There was a significant difference in mean tunnel projection along Blumensaat’s line when analyzing return to sports (73 ± 1.4 and 79 ± 1.7 %, respectively, for projections on return vs. no return to sports, p = 0.02) and complications (73 ± 1.3 vs. 78 ± 1.6 %, respectively, for projections on no complications vs. complications, p = 0.03). No differences were stated on coronal view. These correlations between tunnel positioning on functional outcomes could not be explained by demographic or baseline characteristics.

Conclusion

The clinical relevance of this study is that tunnel positioning along AM footprint and high AM position represented by tunnel projection along Blumensaat’s line is associated with early return to sports on previous Tegner level and better functional outcome in athletes.

Level of evidence

III.     

Association between varus alignment and post-traumatic osteoarthritis after anterior cruciate ligament injury

Purpose

To investigate the association between varus alignment and post-traumatic osteoarthritis (OA) after an anterior cruciate ligament (ACL) injury.

Methods

One hundred subjects with an acute complete ACL tear were followed for 15 years. Anterior–posterior radiographs of the tibiofemoral joint were obtained with a knee flexion of 20°, and the patellofemoral joint was examined with skyline view at 50° knee flexion. Joint space narrowing and osteophytes were graded in the tibiofemoral and patellofemoral joints in the injured (ACL) and uninjured knee according to the radiographic atlas of the Osteoarthritis Research Society International. The alignment of the uninjured, contralateral knee was measured at follow-up, using full-limb radiographs of leg with the knee in full extension. Alignment was expressed as the hip-knee-ankle (HKA) angle. Alignment was defined as valgus (HKA ≤178°), neutral (179°–181°) or varus (≥182°).

Results

Data from 68 subjects were included in the analysis. Varus alignment of the uninjured knee at follow-up appeared to be associated with OA of the injured knee 15 years after an ACL injury (odds ratio (95 % confidence interval) 3.9 (1.0–15.8, p = 0.052)).

Conclusions

Varus alignment of the uninjured knee at follow-up may be associated with OA of the injured knee 15 years after an ACL injury.

Level of evidence

II.     

Long-term follow-up of patellar tendon grafts or hamstring tendon grafts in endoscopic ACL reconstructions

Purpose

Several studies compare the short- and long-term results of anterior cruciate ligament (ACL) reconstruction using bone-patellar tendon-bone (BPTB) graft or double-looped semitendinosus and gracilis (DLSG) graft. However, no studies evaluate the long-term results of BPTB grafts fixed with metal interference screws and DLSG grafts fixed with the Bone Mulch Screw and the Washer Loc. This prospective randomized multicentre study has the null hypothesis that there is no difference in long-term outcome between the two procedures.

Methods

A total of 114 patients with a symptomatic ACL rupture were randomized to reconstruction with either a BPTB graft (N = 58) or a DLSG graft (N = 56). Follow-up was conducted after one, two and seven years. At the seven-year follow-up, 102 of the 114 patients (89%) were available for evaluation; however, 16 of these by telephone-interview only.

Results

Ten patients in the BPTB group and 19 patients in the DLSG group underwent additional knee surgery (P = 0.048), two and three, respectively, of these were ACL revisions (n.s.). The total flexion work was lower in the DLSG group (P = 0.001). The mean peak flexion torque and extension work, however, showed no difference between the groups. No significant differences were found between the groups regarding the Tegner activity score, the Lysholm functional score, the Knee injury and osteoarthritis outcome score (KOOS), subjective knee function, anterior knee pain or mobility. There was no significant difference in laxity between the groups on the Lachman test or the KT-1,000 maximum manual force test.

Conclusions

Both grafts and fixation methods resulted in satisfactory subjective outcome and objective stability. Both these methods can therefore be considered as suitable alternatives for ACL reconstructions.

Level of evidence

II.     

Long-term results of arthroscopically assisted anatomical single-bundle anterior cruciate ligament reconstruction using patellar tendon autograft: are there any predictors for the development of osteoarthritis?

Purpose

The primary purpose of our study was to analyse the long-term outcome of patients treated for anterior cruciate ligament (ACL) tears by anatomical single-bundle ACL reconstruction with patellar tendon autograft. The secondary purpose was to identify predictive factors for good outcome and occurrence of osteoarthritis.

Methods

Sixty-three patients (m:f = 54:9; mean age at surgery, 27 ± 7 years) treated by ACL reconstruction were evaluated with a mean follow-up of 16 ± 1 years using IKDC2000, the SF36, Lysholm and Tegner score, Knee Society score, visual analogue scale for pain and satisfaction and KOOS. The femoral tunnel position was evaluated according to Sommer. It was also assessed in percentage of the Blumensaat line and the tibial tunnel position in percentage of the total anterior–posterior plateau length. The extent of osteoarthritis was graded according to the Kellgren–Lawrence score.

Results

The total IKDC2000 was normal in 20 (32 %), nearly normal in 29 (46 %), abnormal in 12 (19 %) and severely abnormal in 3 (5 %) of patients. The mean total SF-36 was 89 ± 13, the Lysholm score 95 ± 12, the Knee Society score 191 ± 16 and the total KOOS 84 ± 19. The Tegner score decreased from pre-injury 7(4–10) to 6 (2–10) at follow-up. The Kellgren–Lawrence score was normal in 17 (27 %), suspected osteoarthritis in 25 (40 %), minimal osteoarthritis in 5 (8 %), moderate osteoarthritis in 9 (14 %) and severe osteoarthritis in 3 patients (5 %). The femoral tunnel was in zone A in 43 patients (68 %), in zone B in 16 (25 %) and in zone C in 4 patients (7 %). The femoral tunnel position in percentage of the Blumensaat line was 49 ± 3 (range, 44–57), and the tibial tunnel position in percentage of the total anterior–posterior plateau length was 32 ± 6 (range, 21–46). Patients with meniscal lesion at the time of ACL tear showed significantly less favourable outcomes than those without.

Conclusions

Patients treated by the proposed ACL reconstruction technique showed on average good to excellent long-term results. A meniscal lesion at the time of ACL tear was highly predictive for less favourable outcome.

Level of evidence

IV.     

ACL–PCL and intercondylar notch impingement: magnetic resonance imaging of native and double-bundle ACL-reconstructed knees

Purpose

The purpose of this study was to: (1) define the relationship between the ACL and PCL in normal knees; (2) determine whether ACL–PCL impingement occurs in native knees; and (3) determine whether there is a difference in impingement between double-bundle reconstructed and native knees.

Methods

Eight subjects were identified (age 20–50; 6 females, 2 males). All were at least 1-year status postanatomic double-bundle ACL reconstruction (allograft; AM = 8 mm; PL = 7 mm) and had no history of injury or surgery to the contralateral knee. MRIs of both knees were performed with the knee at 0 and 30° of flexion. The images were evaluated by a non-treating surgeon and two musculoskeletal radiologists. Coronal and sagittal angles of AM and PL bundles, Liu’s PCL index and the distance between ACL and PCL on modified axial oblique images were recorded. Impingement was graded (1) no contact; (2) contact without deformation; or (3) contact and distortion of PCL contour.

Results

Seventy-five percent (6) of the native ACL’s showed no contact with the roof of the intercondylar notch or PCL, compared to 25 % (2) of the double-bundle reconstructed ACLs. One double-bundle reconstructed ACL showed intercondylar notch roof and ACL–PCL impingement (12.5 %). Significant differences were found between the native ACL and the double-bundle reconstructed ACL for the coronal angle of the AM (79° vs. 72°, p = 0.002) and PL bundle (75° vs. 58°, p = 0.001). No differences in ROM or stability were noted at any follow-up interval between groups based on MRI impingement grade.

Conclusion

ACL–PCL contact occurred in 25 % of native knees. Contact between the ACL graft and PCL occurred in 75 % of double-bundle reconstructed knees. ACL–PCL impingement, both contact and distortion of the PCL, occurred in one knee after double-bundle reconstruction. This study offers perspective on what can be considered normal contact between the ACL and PCL and how impingement after ACL reconstruction can be detected on MRI.

Level of evidence

Cohort Study, Level III.     

Ten-year clinical and radiographic outcomes after autologous chondrocyte implantation of femoral condyles

Purpose

This prospective study assessed the 10-year clinical outcomes of periosteum autologous chondrocyte implantation (ACI) due to cartilage lesions of the femoral condyles.

Methods

Thirty-three of 45 patients (3 failures, 7 non-responders, 2 others) were available for clinical and radiographic evaluation at 2, 5, and 10 years. Patients were categorized into groups with focal cartilage lesions, osteochondritis dissecans (OCD), and cartilage lesions with simultaneous ACL reconstruction (ACL). Seven patients in the overall series required an arthroscopic re-intervention (3 ACI related, 4 ACI unrelated).

Results

Subjective knee scores and activity scores were significantly improved at 2 years toward their pre-operative levels and then remained stable up to 10 years; however, patients did not reach their pre-injury activity levels. Upon 10-year examination, using the IKDC knee examination form, there were 15 normal, 11 nearly normal, 5 abnormal, and 2 severely abnormal knees. Radiographic evidence of osteoarthritis was found in 45 % of patients (5 focal lesions, 2 OCD, and 8 ACL).

Conclusions

ACI provided safe and stable performance of operated knees over 10 years with a significant improvement toward pre-operative levels. Patients restrained from high-impact knee joint activities, post-surgery, and their knee radiographs demonstrated a high incidence of knee OA in trauma-related lesions. Optimal long-term performance is expected in localized, low-impact cartilage lesions of young patients.

Level of evidence

Case series, Level IV.     

Quantitative magnetic resonance imaging (MRI) morphological analysis of knee cartilage in healthy and anterior cruciate ligament-injured knees

Purpose

To analyze the morphological change in the cartilage of the knee after anterior cruciate ligament (ACL) injury by comparing with that of the intact contralateral knee.

Methods

A total of 22 participants (12 male and 10 female patients) who had unilateral ACL injury underwent MRI scan of both the injured and intact contralateral knees. Sagittal plane images were segmented using a modeling software to determine cartilage volume and cartilage thickness in each part of the knee cartilage that were compared between the ACL-injured and the intact contralateral knees. Furthermore, the male and female patients’ data were analyzed in subgroups.

Results

The ACL-injured knees had statistically significant lower total knee cartilage volume than the intact contralateral knees (P = 0.0020), but had similar mean thickness of total knee cartilage (not significant: n.s.). In the male subgroup, there was no significant difference in cartilage volume and thickness between normal and ACL-injured knees. In the female subgroup, the ACL-injured knees demonstrated statistically significant difference in total knee cartilage volume (P = 0.0004) and thickness (P = 0.0024) compared with the normal knees. The percentage change in the cartilage thickness in women was significantly greater than that in men.

Conclusion

Cartilage volume was significantly smaller in the ACL-injured knees than in the contralateral intact knees in this cohort. Women tended to display greater cartilage volume and thickness change after ACL injury than men. These findings indicated that women might be more susceptible to cartilage alteration after ACL injuries.

Level of evidence

III.

     

Return to sport: Does excellent 6-month strength and function following ACL reconstruction predict midterm outcomes?

Purpose

The purpose of this study was to determine whether patients with excellent 6-month functional testing after ACL reconstruction had (1) higher risk of subsequent ACL tears, (2) superior knee function, and (3) increased activity levels compared to those with delayed clearance for return to sports at midterm follow-up.

Methods

A total of 223 patients underwent primary ACL reconstruction by a single surgeon and had functional and isokinetic testing performed 6 months post-operatively between 1998 and 2005. Of the 223 patients, 52 (23 %) made the excellent group and were allowed return to sport at 6 months, and the remaining 171 (77 %) constituted the delayed group. Rate of ACL graft tear and native contralateral ACL tear was compared between groups. In addition, IKDC and Tegner scores were compared at a mean 4-year follow-up.

Results

The graft rupture rate was similar in the excellent group (3.8 %, n = 2) compared to the delayed group (4.7 %, n = 8; p = 0.30). However, there was a higher rate of contralateral ACL tear in the excellent group (15.4 %, n = 8 vs. 5.3 %, n = 9; p = 0.003). The excellent 6-month group had superior IKDC scores (94.3 ± 6.4 vs. 90.9 ± 9.7; p = 0.04) and Tegner scores (6.6 ± 1.8 vs. 5.7 ± 1.6; p = 0.01).

Conclusion

Patients with an excellent performance on their isokinetic strength and functional testing at 6 months after ACL reconstruction have superior knee function and higher activity levels at midterm follow-up. However, these patients appear to be at greater risk of contralateral ACL injury, which may be related to their increased activity level. When isokinetic and functional testing is used for return-to-sport decisions, physicians should caution patients about the risk of contralateral ACL injury for high performing patients.

Level of evidence

Retrospective Review with Control, Level III.

     

Revision ACL reconstruction using contralateral hamstrings

Purpose

Due to the increasing number of primary anterior cruciate ligament (ACL) reconstructions, the need for revision surgery has risen. The aim of this study was to evaluate the use of contralateral doubled semitendinosus and gracilis tendon (DGST) for revision anterior cruciate ligament reconstruction.

Methods

Twelve patients undergoing revision ACL reconstruction with hamstring tendon were examined at an average follow-up of 3 years. All patients underwent a thorough subjective and objective evaluation, which included a KT-1000 arthrometric evaluation, and a radiographic examination.

Results

Subjective evaluation yielded a median score of 5.5 (range 2–9) on the Tegner activity scale. The mean Lysholm score was 95 (SD 9.5), and the mean subjective IKDC 2000 score was 95.4 (SD 7.8). At physical examination, a negative Lachman test was found in ten patients; one patient had a positive Lachman test with a firm end-point, and one other patient had a clearly positive Lachman test. Two patients had a grade 1+ on pivot shift testing. Only 1 patient showed a side-to-side difference more than 5 mm at the maximum manual KT-1000 arthrometer. Three patients (25 %) showed initial signs of osteoarthritis.

Conclusions

The results of the study show that the use of hamstring tendons harvested from the unaffected knee represents a valid option for revision surgery following a failed primary ACL reconstruction using DGST grafts.

Level of evidence

IV.     

Use of cell-free collagen type I matrix implants for the treatment of small cartilage defects in the knee: clinical and magnetic resonance imaging evaluation

Purpose

Articular cartilage defects of the knee are a common condition for which several repair techniques have been described. The aim of the present study was to assess medium-term results of a one-step procedure using a cell-free collagen type I matrix.

Methods

Fifteen patients with articular cartilage defects of the knee were treated with an 11-mm-diameter cell-free collagen type 1 matrix implant. The matrices were implanted in a press-fit manner into the defect after careful debridement down to the subchondral bone but without penetration of this margin. Follow-up examinations were carried out at 6 weeks, 6 months, and at 12, 24, 36, and 48 months after implantation. Clinical assessment included the visual analogue scale (VAS), the Tegner activity scale, and the International Knee Documentation Committee (IKDC) score. Radiological assessment for graft attachment and tissue regeneration was performed using the magnetic observation of cartilage repair tissue (MOCART) score.

Results

A total of 15 patients (males: n = 6 and females: n = 9) with a mean age of 26.4 years (range 19–40) were treated. The mean VAS improved significantly when compared to the preoperative values (P < 0.05). Six weeks after implantation, IKDC values were slightly lower than the preoperative values (n.s.), but increased significantly at final follow-up (P < 0.05). At 24 months, there were no significant differences in the median Tegner score between the post-operative values and the preoperative values (n.s.). However, after 36 months, a significant improvement was noted that lasted at least up to 48 months (P < 0.05). The MOCART score improved consistently up to 4 years after implantation, with significant improvements already observed after 12 months (P < 0.05). No correlation between the clinical scores and the MOCART score could be perceived.

Conclusion

The present study showed that the use of cell-free collagen type I matrix implants led to a significant and durable improvement in all the clinical and imaging scores investigated 4 years after implantation.

Level of evidence

IV.