Autologous chondrocyte implant (ACI) is a very effective technique in the treatment of chondral lesions in order to restore normal hyaline cartilage. This technique, reported for the first time by Peterson in 1994, is advised for young or middle-aged. active patients with a single painful chondral injury (3/4 grade of Outerbridge scale), starting from more than 2 cm². New tissue engineering techniques with the use of biomaterial derived from hyaluronic acid (HYAFF matrix) provide ideal support for the culture and proliferation of chondrocytes, allowing at the same time arthroscopic implant. There are many advantages of arthroscopic techniques: easy implant and less pain post-operatively; however, the indications for arthroscopic technique are still restricted: single chondral inury, 2–6 cm² in size and localisation at the femoral condyles.

At the Department of Orthopaedic Surgery of the University “ Federico II ” of Naples starting from January 1996 to the present, 29 patients were treated with ACI. Eight patients (six men and two women) had an arthroscopic implant. Median age was 18; in seven patients an OCD of the medial femoral condyle was present and just one patient had a post-traumatic injury of the medial femoral condyle. Hyalograft was used in all cases. All patients underwent CPM starting from the second post-operative day and full charge was allowed after 2 months. All patients were evaluated by clinical examination with IKDC score and functional score (Tegner) at 3, 6 and 12 months after surgery and with a MNR at 6 and 12 months after surgery and then every year.

Good results were found subjectively in 88% of the patients, with a complete lack of pain in 70% cases. Using the IKDC score good results were found in 85% of the cases (average score 90). With the Tegner score we reported an improvement in the level of activity in 60% of the cases.

The MNR images, performed with standard sequences, fat-suppressed and in the last cases with dGEMRIC, showed the presence of regeneration tissue inside the chondral defects, with a signal very similar to that of the cartilage tissue, sometimes slightly deeper.

Our experience shows that ACI is an effective way of treating chondral lesions with excellent results. We think that progress in the field of biomaterials will extend the indications for arthroscopic techniques, also allowing implants in larger lesions and at other sites.

The authors present their experience with high tibial osteotomy for the correction of varus knee, performed wih an open wedge technique (Puddu). This technique allows correction of varus knee with a medial tibial osteotomy open wedge, using a special tibial plate; this plate is fixed with two cortical screws and two spongious screws and is formed by a tooth that prevents the correction from loosening. The aim of our work is the retrospective clinical and radiographic evaluation of 18 patients treated with Puddu technique at the University of Naples.

Indications for this technique are: constitutional varus knee, chondral damage after medial meniscectomy and medial gonarthrosis. From June 1999 to the present we treated 18 patients (13 women, five men), median age 54, with high tibial osteotomy with Puddu technique at the department of Orthopaedics and Traumatology of the University of Naples. Before the osteotomy we normally perform a knee arthroscopy to achieve a correct articular balance (evaluation of articular cartilage, menisci and ligaments) and to treat associated lesions. All patients were evaluated by clinical examination with IKDC score and X-rays. Median follow-up was 30 months.

Results are very good with an important improvement in pain and disability. Vascular and neurological complications were not found in any of the patients; all the osteotomies had a strong consolidation and showed good correction of the deformity.

High tibial osteotomy with Puddu technique in our opinion seems to be an effective technique in the treatment of medial knee arthritis and in the correction of femoral-tibial axis. It is an easy, reproducible and trusted technique and in our opinion recommended over the traditional tibial osteotomies (closed wedge osteotomy, dome osteotomy and osteotomy with external fixation, etc).

New magnetic resonance imaging (MRI) techniques for imaging cartilage have an ever-increasing role in the evaluation, diagnosis and monitoring of joint disorders. Relatively few studies have been undertaken to determine the long-term response of the cartilage to different treatments such as microfractures, osteochondral autograft, osteocondral mosaicplasty and autologous chondrocyte transplantation.

Intravenous administration of gadolinium diethylene-triamine-pentacetic acid (GdDTPA) on MR represents an exciting possility to explore and validate strategies for repairing cartilage. GdDTPA is an ionic contrast agent that is administered and is given time to penetrate cartilage where it is distributed according to the concentration of the charged molecules in cartilage matrix. The main macromolecular constituents of cartilage are glycosaminoglycans (GAG) and collagen. GAG have abundant negatively charged carboxyl and sulphate groups that by osmotic effect give the cartilage stiffness. GdDTPA enhances the cartilage that is depleted of GAG, then is distributed in an inverse relation to the concentration of the negatively charged GAG. In the normal articular cartilage tissue GAG has a lower concentration at the articular surface and a higher concentration in the deeper zone as histological and GdDTPA on MR studies have confirmed. Many problems we can consider to be the choice between i.v. contrast administration and intra-articular injection, which is an invasive route. Furthermore, the time course of penetration of Gd-DTPA into cartilage depends on the cartilage thickness. The time for maximum signal enhancement may vary from 45 min. for the thin ventral femoral condyle to about 4 h in patellar cartilage. Progress has also been made in evaluating the distribution of GAG in patients with osteoarthrits.

Our goal is to gain information regarding the state of the cartilage in follow-up of autologous condrocyte transplantation correlated with the clinical implications. The severity of the focal defect of cartilage in one negative result is estimated from the morphologic appearance of the hyperintense lesions on contrast-enhanced MR images. In agreement with Gillis et al. we could observe clear time-associated differences of GAG density in the patients who received autologous chondrocyte implants.

Chondral injury has become one of the most difficult problems to solve in orthopaedics. This pathology is very common: Curl et al. founded an incidence of 63% of chondral lesions (2.7 lesions for knee in 31,156 knee arthroscopies) with a 20% rate of lesions of grade IV of Outerbridge.

During the past few decades many techniques were developed: with these techniques the lesion is just reparied with the formation of fibro-cartilage tissue with biochemical and bioelastic characteristics very different from the hyaline cartilage tissue.

Microfracture technique : This technique, proposed by Steadman et al., utilises hand-drills to create numerous perforations in the subchondral bone at 3–4 mm apart. Indications for this techniques are lesions from 0.5 to 2 cm² with an outlined border in patients with low functional demand. Osteochondral autograft transplantation (OATS, mosaicplasty): Osteochondral autograft transplantation is indicated for isolated lesions from 1 to 3 cm² or in OCD. Outerbridge et al., in a study of 10 patients with 6.5 years of follow-up, achieved good functional results in all pateints treated with this technique. Autologous chondrocyte implant: ACI, reported for the first time by Peterson and colleagues in 1994, is advised for young or middle-aged, active patients with a single painful chondral injury (3–4 grade of Outerbridge scale), starting from more than 2 cm². They. reported good results in the treatment of chondral lesion with a long follow-up (2–10 years). New tissue engeneering techniques with the use of biomaterial derived from hyaluronic acid provides ideal support to the culture and proliferation of chondrocytes, allowing at the same time arthroscopic implant.

Today there are many options in the treatment of chondral lesions, but no one technique can be considered the gold standard. ACI in arthroscopy is a more promising technique in the treatment of the chondral lesions, but the indications are still too restricted.

Neglected rupture of quadriceps tendon is an infrequently occurring lesion resulting from sport, but it is very interesting as regards the physiological and functional repercussions. The lesion is common in football players. The pathogenesis is a flexion trauma of knee. Many authors point out the importance of a pre-existent degeneration due to exogenous and endogenous factors. Pain, inextensible knee, ecchymosis, axe hit are a common presentation in acute events, difficult knee extension and pain in chronic. X-ray study shows calcification at the tendon-bone junction.

The treatment of neglected rupture of quadriceps tendon is surgical. If a defect of 5 cm or more is present between the ends of tendon the fascia lata can be used to correct the gap. When the ends can be apposed an end-to-end repair is possible. We treated a neglected rupture of quadriceps femoris muscle tendon in a bodybuilder with a particular technique: we stripped and harvested the semitendinosus and gracilis tendon and sutured them together. Then we made a transverse hole in the mid-portion of the patella; the tendons were passed through the transverse hole in the patella and sutured with the lateral, medial and intermendial vastus, and with the rectum femoral. At 6-month follow-up the patient has no pain and stability is improved, a practical range of knee motion regained. Full forceful extension is not completely restored.